One thing to pay attention to is the direction you yarn over. You can do it in either direction (clockwise or counterclockwise) as long as you stay consistent throughout the whole project. When I do amigurumi I usually do the opposite direction from my usual crocheting. Yarn under, if you will, rather than yarn over, if that makes sense.
The first couple of things I made I think I did them normally and they were ok, but I may have switched back and forth without realizing it. Then I read that some people do the yarn under for amigurumi and that’s when I realized that I needed to pay attention and do it consistently one way or the other.