I just bought ashe and i was wondering if i could get any tips on using her.

Head on over to the guides and strategy section of the forums and find the sticky that lists guides, find and read a couple Ashe guides and apply what you're learned.

Ashe is pretty easy imo. My one tip with Ashe and all squishys is do not initiate. Stay back and attack from as far away as you can in team fights. If possible have someone else take the hits since you are the carry.

Also practice kiting it's pretty big with Ashe.

With your arrow always shoot down lanes not across better chance of hitting, and try being farther away then you do use your arrow for a longer stun.

As said Ashe is pretty Squishy, but that early game you can initiate a little if you wait for focus passive to get to 100% and then auto attack hero and hit him with volley. Very good for early game harrass. Don't waste money on Attack speed items, except last whisper which you usually pick up around mid/end.. go for straight dmg and work towards infinity edge. For boots I usually go mercury treads be cause ashes is squishy and needs to be able to get outa cc's fast if you get do get caught... you can find alot more help in strats on here..

At start I usually get dorans sword and 1 mana pot, allows you to stay in lane longer which = more harras and possible early kill and longer farming without wasteing time pilling.

Stay in the back with Ashe. Play her like a mage. She has a little bit more HP than most straight mages, but her attacks are either single target or can be blocked by creep waves. That makes it hard to harass. Buy a Doran's item or boots at the start of the match to help avoid early ganks, and don't be aggressive. If you're in lane with someone who can stun or slow, be very careful. One stun or slow can mean your death, especially if one of the people you're laning against is ranged. or has ignite.

Late game, stack attack damage and move speed. Your goal is not to kill people. It is to slow them with your frost arrow. Because of that, be very wary of trying to gank anyone on your own or even in duos. You are tremendously useful in team fights, but if the enemy focus fires you in, say, 3v3 or 2v2 fights, you become a liability. Play with that in mind.

All said, she's an excellent choice to complement a team full of slow but hard-hitting champs. For teams full of fast champs, though, or teams that already have a lot of slows and stuns, Ashe may not be the best choice.

Yet another reason why you shouldn't lock in until everyone has chosen their champs.

Another main point of ashe is to only use frost shot when you need it, when a champ is fighting and not running leave it off until they start to run, also leave on frost shot while attacking creeps. 8 mana may not seem like much but the more you save the more likely you'll have enough mana to get that enchanted crystal arrow (ECA) or extra volley

announce when your ult is off cooldown, also ping where the arrow is going if you already fired it.

Last tip is to pay attention to the map, frequently glance at other lanes once your 6 that way you can start to plan if you need to send in an arrow.

Also don't forget that you can use your arrow to save your allies and yourself from ganks. I can't count how many times I've saved allies who barely survived a gank and were running away. You can also use your arrow to initiate a gank, if you use it from far enough you can keep them stunned long enough for your teammates (and yourself) to catch up. After that you hit them with a volley and keep them slowed with frost shot as you cahse them down (if they even had enough hp to get away).

Learning to animation cancel is quite important.

Just when the arrow has been shot you move either back or forward during the time that it takes before you can attack again.

http://www.youtube.com/watch?v=dK4PwnV59ik phreak shows it at 2:08

i personally build just attack damage and crit chance. building attack speed means to do any real damage, you have to hold still and fire a bunch of arrows; i.e get killed by CC and 2 hits since you're squishy. with huge attack damage+crit, you only need to hold still for a bit to deal the equal amount of damage. go with either the sorcerers treads if you're vs casters, or get the boots that give +2, then after 5 seconds +5. get a phantom dancer for the decent+attack speed so you don't attack so slow and for crit chance, and an infinity edge. that alone gives you 50% crit chance i think and decent damage just with 2 items. other than that, just build however you need. I used to use ashe a bunch and this usually gave me 3-4kd ratio.

hope this helps