Farming and trading

I'm working on my farming and I'm able to get a solid cs score by 10 minutes, but I'm struggling with farming and trading. I can either get a pretty good cs or I can outpoke and have lane dominance, but I'm having trouble to multitask and both poke and keep my cs score up. I'm also have trouble keeping my cs score up as the game goes on to 30+ minutes and I spend more time teamfighting and roaming between lanes. How should I go about this? My main is azir but I have this problem in general.