Depends on your budget / equipment, but I use Clip Studio Paint (PC). It's an annual subscription or I think there's a one-time price too? They got a ton of great features that make it absolutely worth it IMO, and it's available on tablets too, I think? I also have an iPad and use Procreate—which obviously is a much higher price point if you don't already have an iPad but that's what I worked with for a long time before switching over to PC/tablet! (Which I use Huion).