ADC queries

So, i main of course adc, some games I do amazingly well, then just randomly the next game i get a D- , I'm pretty sure its not coincidence that i just had a bad match.. I like to think i average around 150 cs around 15 mins (when i say around i mean like 140 etc.) but my csing is absoloutely awful, for example i dont poke anymore, just focus on cs and get drained. Also i just feel like i do badly in matches a lot of the time, e.g (yes sometimes i have good matches)i play safe early game and don't feed and get the occasional kill but then late game i kind of do well harassing but yea xD

Some of you will get what i mean, some won't.

What I'm really asking for is: Can I please have some pointers for being a good adc please?.

Finally which champion should I use just in case gets banned: I own - The champs who I play decently.

Could I also have tips on playing these champions specifically please?

Thanks a TON [slayer-pantheon-thumbs]