For ranked and draft pick, communicate with your teammates. Many a times they won't but it's still important. Even if you call roles, the thing about draft pick order is that they are draft pick for a reason. Calling your roles won't guarantee you get it because whoever gets the first pick order before you has priority in role selection. With that said, most of the first two picks should not be top or mid. For instance, if you are the first in the draft pick, you should refrain from choosing mid or top because they will get easily countered.
It's the players that really count and not the counter... but being countered will put you at a huge disadvantage. For example, Riven vs Olaf. I have stomped on a few Olafs as Riven but TBH they were just bad Olafs who always missed their axes. Gangplank vs Pantheon, it'll be a nightmare laning game for Gangplank. It is better for your bot lane to get countered than your top or mid because you will at least have a support to provide presence. You just have to be smart about how you do champ select in draft or ranked. Especially in ranked. You want to give your team the biggest advantage as possible.
So figure out a few champs that are OP or very nice laners for every lane. Make sure that you try to learn champs that counter a lot of the more popular champs that is selected; Singed, Jayce, Riven, Jax, etc. OR, if you are specifically good with a champ with amazing skill set and you can still excel against your counter, then do that champ because it'll pay off late game. You WILL come across people who refuse to communicate and just insta pick the champ they want to play. When this happens, just fulfill the roles needed for your team. I understand it's infuriating and everyone else agrees but if you troll pick with him, it'll just make it worse on your teammates.
ALSO keep in mind no matter what your team should have at least one tank, good to have a bruiser, 2 carries (AP and AD) and support. If you see that top lane and bot lane chose fairly squishy champs with no tank, go tanky jungler. Don't just pick Master Yi Jungle and say you will go tanky Yi. Try to find a tanky jungler that will excel even if you sacrifice damage. This is why Amumu is a great jungler IMO. You build him AP Tanky and he is insane; with his W, % of your enemy's health drops as DoT as well as incredible ult CC that can change the tide of battle.