@AphiosEy As U-USER2000 says, the shading doesn't have to be in circles, it can be lines, here try this :-
1) Take the outline colour of a drawing you're working on.
2) Go near the part of the pants where you want to shade.
3) Draw straight lines where you think the shadows should go.
(TIP :-
• Make the lines closer to each other where the shadows are darker, and slowly draw them slightly seperated where the shadow is not.
• Don't change the thickness of the brush you're using, the lines should be thin, (or thick) and it should be uniform :)
• You can refuse to use the outline color if you want, but as per your artstyle, I'd say this is the best advice for you :D
Again, this is just how I do it and you can refuse to do so, I'm just saying what I'd usually do hehe.. )
Emi~~~•°:*^