Hello, my Name is BRA demeister, I`m an ADC Main since Season 5 and play on the EUW Server.
I peaked Plat II last season and enjoy playing Samira a lot.
I learned to love her, since i spamed her every ranked game with my duo partner (Thresh Main).
I'm not the best player from the game-decisions side, but i think i know quite a lot about Samira Gameplay.
In this guide, i want to show you the basics about her Items, Runes, Matchups and Gameplay to learn you how to carry yourelf out of low elo.
Why Samira? I played every ADc to a certain Point. IMO its not that hard to play a new ADC if you know the basics about the role (positioning, when to engage, powerspikes, lane controll). But I´m the kind of ADC that wants to snowball, punish enemys for mistakes, take 2v3. 2v5 or even 2v5 fighst if possible and who can carry the whole team. Thats why i learned to love Samira.
Of course thats not possible with every champion and especially not every game (even with Samira).
But imo Samira is a consistent good pick in every situation, especially if you have a premade with an engage/cc supp (Leona, Nautilus, Alister, Thresh, etc.)

Early Game:
The early game depends a lot on your support. If you have a engage/cc support, you always want to get lvl 2 first and try to go on them, if they dont respect you. But if you a enchanter or poke support, you want to farm up for the mid game, pick fights only if you know you win them and chill until lvl 6.

Mid Game:
In the Midgame you try to force fights around Drake/Herold. With Samira and her reset on her e, you can carry fights 3v4 or even 2v4 (if you have shieldbow and collector). BUT you never want to engage first if they have at least on frontliner. Try to stack your Conq and Passive on the tank, and ping your team if you are full stacked. With your passive you can follow up on cc and clear up the entire enemy team.

Late Game:
Same as in the Midgame, you never want to engage first. Try to wait for the right moment, save your w and go all-in after your team sets up the right opportunity and you are fuly stacked.
But remember, while your dmg-output might be even higher than in the midgame, the enemys will kill you faster, even with shieldbow and BT. you wont be as hard to kill as in the midgame.