Welcome to Gaia! ::

Lately I've been trying to develop my own style for everything, but the one thing I'm feeling most conflicted about is my style of shading. Right now cel shading is difficult for me because I'm not confident on where the shadows should go.

I just wanted to hear a few people's opinions on which style works best with my art, half-cel or soft?

Examples in order from newest to oldest:

Half-cel
[X]
[X] Chapter cover I colored for Child of Thorns
[X] From a Disney coloring book

Soft
[X] Work in progress, I'm not sure how to color the shirt and tie sweatdrop
[X]
[X]

Critique on either shading style is welcome, but I don't want critique on anatomy since that's not what I'm asking for help on right now.

If you're uncertain I don't think you should force yourself into a particular style. Just go with what you're most comfortable with.
Maybe introduce some complementary colors and greys in your shading to add extra depth.

If you don't already know that one if for you, then maybe neither of them are? When you land on the type of work that speaks to you, you'll know. Keep trying lots of new things. Remember to take some time to play around.
Personally I can't stand cell shading. I find it tedious.
One thing about your coloring, you've got great choices of colors, but some more variations of tone in the light and shadows might be something to try.