Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
In the early game caitlyn is often found lacking the ability to really out damage your opponents. its not impossible, but it can certainly be tricky. so I have decided to opt out on buying any items other than the totem until you have at least enough gold to buy the B.F. sword. recently i have actually descovered that with a good support you can easily hold lane till you have 2600 gold at which point you are able to buy the b.f. sword and get a start on the rapidfire cannon.
after begining items/how to lane
Due to the update that riot gave caitlyn she can seem a bit under powered early game which can be seen to continue into the late game. however, that's not the case due to her traps. as you level up your snare ability you gain increased headshot damage when hitting someone with your auto while they are snared. this can heavily raise your damage early game to compete with champs like jhin who have a higher base damage than you do early game. it is also important to take note of the fact that attacks from the grass is a great way to cs and get in a few extra headshots as her passive now scales twice as fast while in the grass.
so around level 9-11 you should be sufficiently able to start team fighting. however, you have to be careful as you are squishy and still a bit slow. so after you finish your core items i suggest building your boots if you haven't already done so. of course there is a bit of wiggle room here as you can find yourself just constantly getting ran over by the faster champs so you can build the boots before finishing and/or even starting infinity edge.
as always late game is where caitlyn is really able to shine. with her abilites sitting at fully leveled she is able to chunk out health with a good headshot to a squishy champ and armor is almost none existant due to her armor pen. this certainly allows you to hurt much more in a team fight as well as controlling the flow of the battle with your traps by using a good balance betweeen defensive and offensive traps. at this point it is also a good idea to make sure to start comboing your netting into your headshots on an enemy champion because it helps to get them lower on hp while at the same time slowing them down and getting you out of a sticky situation.
just an interesting note. your headshots from the yordle traps can crit for 450% due to the buffs caitlyn has been given.