Nice job, you have a really nifty style. Something highly recommended among digital artists (I’m not one myself so don’t quote me on this) is to use burn and dodge tools sparingly. Instead, try picking a nice dark shade of the color you’re shading (dark green for your dragon) and then use the pressure sensitivity of the tablet to affect the opacity of the dark color. Paint over the area you’re shading, gradually laying the darkness down until it’s at the point you want.
Do a similar thing for highlights but with a light color. Try not to paint anything totally white, as a white area would mean overexposure, which doesn’t happen in real life very often, instead paint a light gray (or light green for your dragon) and see if you like it more.
Something else you can do if you don’t think your image looks correct form-wise is turn it upside down (rotate your head lol) and see if you can correct anything from there (this may be very hard to do with a tablet.)
REMEMBER: None of the things I’m talking about are rules set in stone, they are merely guidelines to help with realism. Of course, do whatever you think looks best.
Hmm…I’ll try pulling up a few links for various video tutorials about art in general. You don’t have to find program-specific tutorials to learn anything
Keep at it!
(quite possibly the longest post of mine!)