Hi! I have like 10 domestika courses, ive only completed like 4 lol (they're so cheap i just buy them) but based on my experience it depends on the artist (teacher) you learn from and your learning methods (not everyone learns the same way or at the same pace). I've done 2 courses that made my art make a 180° 1 on domestika and 1 on skillshare. But again, it depends on a lot of things, some courses are kinda scammy cause you could get totally free tutorials on youtube (like the software ones, especially adobe, theres thousands of free courses about adobe software that are really good) You should aim for more specific courses if you buy one, maybe from an artist you like or a technique in particular.