Whenever Samira has max Style points, she will be able to use her Ultimate R. Avoid trading with her when she has max points.
At level 6, Samira’s kill pressure increases as long as she has max Style points. Take care as she may look for an all-in when she is at point A.
Samira is at her weakest when she is out of mana or out of Style points. Looking to fight when she has very little of either of them will increase your chances of killing her.
In team fights, lock her down with CC at the start of the fight so she is unable to dish out damage. CC will also stop her Ultimate R prematurely, so try to lock her down quickly if she uses her E.
Samira will often be left alone in the mid lane to farm during the mid-game. You could use this as an opportunity to catch her and her Support out of position and force an objective afterwards.
Try to force fights as soon as you spot Samira or when she is on low Style points. Delaying a fight will allow her to get Style points and keep them for the upcoming team fight.
Keep a constant eye on how many Style points she has. The closer to S rank, the more mobile she will be and the deadlier she can be too. Post 6, she cannot use her Ultimate R unless she is fully stacked on Style points
Samira is an incredibly mobile champion. To reduce her mobility and increase your survivability, try and keep the minion wave closer to your side of the map. This will make it impossible for her to use her E aggressively. If you’re a weak ADC in the early game, definitely keep the wave closer to your side of the map.
Playing around her W in lane is crucial as it can block projectiles (auto attacks). Whenever she uses this ability to trade with, try to abuse the cooldown and go for favourable trades.