Alright. So, as of right now, I'm a B3 ADC main, and I just can't seem to master it. Everytime I think I've got it down, I realize that I'm actually really bad at one thing, and once I think I've got that down, I look at another and realize that I'm still not good at it. Any tips? 
Main, BTW
Drunk Rummate1 voteswhat kind of tips are you looking for?
strategy? or mechanics? or item builds and their strengths and weaknesses?
ADC is one of the easiest roles to carry yourself out of with bronze, you just have to position yourself well in teamfights and do a lot of damage most of the time. Bronze players are bad at focusing ADCs. They either tunnel and waste a lot, which you can avoid by positiong well; or they ignore you and you do way too much damage and win the fight.
Also, I'd recommend against Caitlyn. She's appealing because she's safe, but her strength lies in turret sieging and fast pushing and she doesn't deal very much damage compared to most other ADCs. In Bronze you're unlikely to run into a team coordinated enough to siege turrets while protecting you, so it's better to pick ADCs that have high dueling and/or teamfight potential (graves and lucian are great).
The Chin1 votesAll the champs you play are good in lane, try some that are more mid/late game focused
IMO it's extremely hard to carry games with lane bullys, unless you get like 4 kills in lane you're going to have a real hard time closing out the game. To get that fed in lane you're kind of relying on your opponents to make mistakes, which isn't the most reliable way to win games.
Hardstuck G41 votesWho would you recommend? I also like 
and 
, but I don't play them as often.
The Chin1 votes is really good, I'm a HUGE fan of but she's a relatively risky pick.
I'd say add corki and either 
or 
to your champ pool so you can play a lane bully/mid game/ late game carry depending on what the team needs.
Personally I like
is the champ I climbed out of bronze with
Hardstuck G41 votesI play a bit, but I could add , wouldn't be hard, I think
Shogunai1 votesWhats are you concerns or area's where you feel you need to improve? I think we can better help you if you gave a little more detail. In addition I view ADC as chess, the entire role is situational. Maybe your making bad decision making at times or maybe your opponent is a bit more experienced as you an not making enough mistakes for you to capitalize on. So don't auto assume its you. If you need help with builds I can help you with those if that your issue in game. If its creep score related which is a big part of ADC then I recommend you practice in customs. So t really depends on what you think you need help with.
Hardstuck G41 votesIt's mostly decision making, I've practiced CS to the point where I can hit the first 3 waves perfectly, even under stress and while poking. I know how to counter build, but decision making is bad. I like to take risks, and that's been known to really crush my K/D
Shogunai1 votesDo you think possibly that your support is being helpful enough. I use to main support in season 4 an I had to adapt to how my adc played. I could really tell the difference between a confident adc an a non confident one by the first few ways. Maybe find yourself a support main friend an build a some synergy with him/her an see if that makes a difference. A lot of times if the two parties don't mesh well mistakes can be very punishing an cause a lane loss very early in the game an ultimately may cause for a game loss. Not trying to push the blame on others but this could easily be it. If you have a support that is not being very useful then its pretty much a 1v2, 1v3 when the enemy jungler is ganking.
Blueclaws1 votesIf you are having trouble with position etc. Try running some ARAMs with adc's. All the team fighting should help you learn to position yourself better. If not it's only an ARAM :).
Maybe try running a custom with your ADC of choice and see if you can beat the bots 1v5. If I have trouble with a champ I'll just do that to try out somethings. Sometimes it works for me.