I find keeping a mental checklist of yourself while playing RTS games helps quite a lot. I hope this guide can help those unwilling to listen people review their actions before doing weird things. This is based on some mistakes I've seen people make when playing or even mistakes I've made myself earlier on and have learnt from and many helpful reminders I've seen scattered around the forums, so credits to them if you spot them ;D

Sorry if this is a bit too much and it's quite hard to make a tl;dr vers, its a guide anyways, supposed to be long and possibly boring :/

Am I following the universal do's and dont do's?

Do's
-Checking the mini-map for missing players instead of always relying on mia calls
-Call mias
-Practice new champs/builds in practice till I am confident in using it instead of trying it out in normal/ranked and possibly ruining other's games
-Do I remember who has which summoner spells?
-Do I look at other player's mana bars?
-Do I watch carefully for buffs and debuffs on everybody?
(Shen's ult, Zil's ult, Blood boil)
-Do I type into chat when I should be paying attention to the game?
-Do I use all the active abilities on my items?
-Do I use hotkeys to play the game more efficiently?
-Do I give constructive feedback?

Don't do's
-Attempting to kill someone without thinking of the consequences of it
(Can he kill me instead?) (Are his allies close by to provide back-up) (Can I kill him and get away with it?)
-Attempting uneven team fights
(Is one or more of my team mates jungling while the enemy team is ALL gathered up?)
-Insulting a fellow team mate
(Is it really their fault?) (Is keeping quiet better than starting a flame war?) (Is talking in a polite way and giving helpful
reminders to them a better alternative?)
-ALWAYS assuming that a certain build is the best and if someone else builds much differently, it automactically = noob
(Have you ever used that build yourself before and noticed it yourself that it really isnt viable?)
-Do I give negative feedback

Before Queuing
-Do I really have enough time for 1 complete game? Even a long one?
-Have I read the latest patchnotes?
-Should I finish my sandwich/ ice cream bar/phone conversation first or play with one hand?
-Am I too sick, sleep deprived, drunk, or aroused to sit down and play this game to the best of my ability?

Champion Select/Drafting
-Does my team have at least one teleport, one exhaust, and maybe one clairvoyance?
-Am I about to accidentally enter the game with Annie using my "Just 4 Yi" runepage?
-Have I played with or against any of my opponents before? Can I capitalize on being somewhat familiar with their playstyle?
-Is Armor or Magic Resistance a better buy against the enemy?
-What role does my team need? Do we do both physical and magical damage? Are there too many squishies? Would our team lane better if I picked a jungler?
-Is there anything suspicious about the enemy's summoner spells?
(5 Teleports, or Revive/Teleport)

Laning and early game
-Am I sure I can draw first blood without facing consequences?
-Am I sure that I am last-hitting enough/properly to farm?
-Am I helping my team-mates properly?
-Am I sure no one is hiding in the side bushes to attempt to murder me and can succeed?
-Do I need to use the bush?
-Does the enemy know I am in the bush?
-Am I harassing properly?
-Can I really flush the dude in the bush out without dying by using my face to check it?
-Can I attempt a 2v1 without dying while my laning buddy is away ganking/shopping/healing?
-Am I being too aggressive/defensive/passive?
-Is there anyone missing that can gank me while I attempt to push the turret?
-Am I turret hugging when I am at a disadvantage?
-Are there any wards or does anyone have an oracle when I am Twitch/Shaco/Eve?
-Should I help the lanes that are losing by ganking?
-Can I win the gank without casualities?
-Can my lane mate handle the lane by themselves if I leave for a bit?
-Are too many minions building up?
(Minions can help turn the tide in a fight)
-Can I push a turret without harm if im too far away to help a lane getting targeted?
-Can I turret dive a turret hugger and get away with it?
-When the enemy does JUST enough damage to kill me, do I facepalm because there is a Red Elixir in my inventory?

Late/mid game
-Who is the carry of the team?
-Can we directly challenge the opposing team and win?
-Do we need to set-up a trap and lure?
-Am I jungling excessively when I am needed in team fights?
-Is there any possiblity the opposing team will try to backdoor?
-Am I doing my role properly in team fight?
(Tanks: Be the initiator, prevent opposing team from killing the carry, die for team mates if needed)
(Carries: Targeting the right person, using all skills properly, staying out of harms way [only for ranged carries])
(Support: Heal, revive, whatever you do to the right person and at the right time)
-Am I stunning/silencing/blinding/snaring/slowing the right person?
-Am I pushing their tower instead of jungling/shopping after I aced/killed off most of the opposing team?
-Do I deserve my kills?
(Were they ks's or did I feed a bit but covered it up later on with team kills?)
-Do we need to back off and when?
-Are there wards at Baron Nashor/Dragon/Buff Areas?
-Do I check tab for revival times of enemies while we push?
-Am I giving unreasonable commands/advice to my team?
(Think of potential ways it may backfire or risks)
-Do we need to leave someone to defend the base?
-Are my items tailor-made for the enemy team or do I buy the same items every game?
-Does my team have priorities on who to focus in team battles?
-Is there a chance for me to find and kill the enemy jungler?
-Is someone on my team saving a CC for Kat/Nunu/Galio/Karthus/Fiddle?
-As Shen, Ashe, Soraka, and TF, do I scan all three lanes constantly after I have my ult?
-Are there specific ways for me to counter the enemy?
(Banshee vs Blitz, Executioner vs Mundo)
-Are we spaced far apart enough so as to not feed Amumu, Nunu, Kat, Fiddle, or Galio a Pentakill?

The Art of Tanking
-Am I initiating for my team?
-Am I preventing the other team from killing off our main DPS/Caster?
-Am I leading the team around to potential successful ganks/death traps?
-Am I building the right items to tank for my team?

The Art of DPS-ing/Caster-ing
-Am I targeting the right person?
-Am I far away from harm/backing off if needed?
-Am I building against XXX correctly?
-Am I behind my tanks?
-Am I using my spells properly/most efficiently?

The Art of Support
-Am I using my spells properly/most efficiently?
Need help in this section, I don't play support champs at all...


Any advice on what to change/add/remove would be greatly appreciated

Thanks to for advice/editing:
zerorei
FireFa11 (add-ons)
Cueballmac (thread name change)


23/08/2010 Guide created
5/09/2010 Added FireFa11's add-ons, Edited parts that could be misunderstood
27/10/2010 Edited, updated and added some stuff

This is a very unique style for a guide, good job

Who the heck is "sure" they can draw first blood? Otherwise a lot of great advice, although you might help some people by explaining complex ideas (like the art of tanking) more thoroughly.

ALL OUT OF ORDER:

Do I remember who has which summoner spells?
Do I look at other player's mana bars?
Are my items tailor-made for the enemy team or do I buy the same items every game?
Does my team have priorities on who to focus in team battles?
(Before you start) Does my team have at least one teleport, one exhaust, and maybe one clairvoyance?
(In lane) Is there a chance for me to find and kill the enemy jungler?
Do I watch carefully for buffs and debuffs on everybody? (Shen's ult, Zil's ult, Blood boil)
(Before you start) Am I about to accidentally enter the game with Annie using my "Just 4 Yi" runepage?
(Before you enter queue) Do I really have enough time for 1 complete game? Even a long one?
(Before you start) Have I played with or against any of my opponents before? Can I capitalize on being somehwat familiar with their playstyle?
(Before you queue) Have I read the latest patchnotes?
Do I type into chat when I should be paying attention to the game?
Do I use all the active abilities on my items?
Are there hotkeys I can use to play the game more efficiently?
Is someone on my team saving a CC for Kat/Nunu/Galio/Karthus/Fiddle?
(Before game) Is Armor or Magic Resistance a better buy against the enemy?
When I ping, is there any chance that my message can be misunderstood?
When the enemy does JUST enough damage to kill me, do I facepalm because there is a Red Elixir in my inventory?
(Before you queue) Should I finish my sandwich/ ice cream bar/phone conversation first or play with one hand?
(Before game) What role does my team need? Do we do both physical and magical damage? Are there too many squishies? Would our team lane better if I picked a jungler?
(Before game) Is there anything suspicious about the enemy's summoner spells? (5 Teleports, or Revive/Teleport)
As Shen, Ashe, Soraka, and TF, do I scan all three lanes constantly after I have my ult?
Are there specific ways for me to counter the enemy? (Banshee vs Blitz, Executioner vs Mundo)
Are we spaced far apart enough so as to not feed Amumu, Nunu, Kat, Fiddle, or Galio a Pentakill?

And the most important question to ask yourself before queueing in a ranked game:
Am I too sick, sleep deprived, drunk, or aroused to sit down and play this game to the best of my ability?

Edited a bit and added FireFa11's advice

TL DR (Did read) +1

Although the phrase "MENTAL checklist" might be a little bit distracting, I'd rather have it as PLAYER checklist instead.

great work in progress. very hardcore to remember all that, but i like it. +1 and bump.

This list reminds me of the list given to me in Drivers Ed, the list which tells you all the things you should mentally go over before and while driving.

...

Yeah, tl;dr.