welcome to my first guide i built this guide because i thought people should see what cait can do when she has enough CDR this build is mana HUNGRY it actually uses enough to justify clarity
and it is designed to scale well into late game by then end if you have a complete set you will be throw around your Q and E so much your fingers might get tired.

you want to start off with the pendant so that you can harass the hell out of your enemy if you arent hurting for mana then somethings wrong. once you have about 1000 gold go back and get tear of the goddess and boots. after that save up for manamune because you should have your ult soon (if not already) and you need to bonus damage to make it work after that go for boot of mobility. her biggest weakness is her speed and having these boots makes all the difference in the world.
next go for brutalizer so that you can bump up every stat that this build focus' on AD ArP and CDR after that go for bf sword.
now you have a choice if you need more Arp get cleaver if you need AD get bloodthirster, and if you need a bump to both and CDR go for ghost blade however you want to eventually get all three.

caitlyns abilities make for some of the best harassment around if you can get the proper combination down no one will want to get near you

Piltover Peacemaker: this ability should be though of one half of a whole, while you can use it to farm it also can be use in combination with 90 cal net to lay down some serious pain ill talk about that in detail last

Yordle snaptrap: this ability is not my favorite but it can be very handy when side laning as insurance of a get away put it in the grass where your enemys will run right in to it. it will give you vision and may sometimes be just the thing you need to finish them with your ult.

90 cal net: once again this is one half of a whole use it in combination with piltover to lay down serious pain. but also remember that this is your get away move when you are on the run use it as a flash to catch up or if you are being run down use it as a flash away that doubles as a slow.

Ace in the Hole: like the name suggests this is your last chance attempt at getting a kill in a fight for the love of god dont waste it as an opener i've seen too many caitlyns do it, and thats not its purpose. often times you wont even have to use it if you have enough output but if you save it, it can make the difference between a kill and them getting away.

how to combo piltover and 90 cal: the trick to it is hitting them in rapid succesion and knowing which one to use first in what situation. when on the offensive you hit piltover first with an immediate follow up of 90 cal this move allows you to tower dive w/o taking any damage from the tower. when on the defensive hit 90 cal first then piltover this move keeps you covered by the tower and out of their damage range plus lets your ally swoop in while they are slowed and keeps the enemy in tower range longer.

this build is made to focus on using your abilities and not to sit there auto attacking. Its an active build so it takes some getting used to but once you understand this build you can hurt so much in a team fight.
with this build you have a wave nuke on a 3.6 sec cooldown and your jump/slow on a 7.2, i rarely use snaptraps but thats a matter of practice not preference
like everyone says please try before you downvote. this is also my first time posting a build so i would love to hear some constructive criticism