Wow! Good for you to keep going! I especially like the last one. The face being hidden adds a lot of mystrey and the obvious weight of the heavy tree being easily held by the person captures your attention.
In regards to reference photos, I’ve done both but have found my strongest work almost always results from using a reference photo. You’re not a bad artist if you can’t pull it all out if your head! No one really does (or at least they never show you the five thousand sketches they did previously). Light, shape, shading, angle are all easier to draw more convincingly if you have some example.
The trick is to use a photo well. Two examples being human figures and dragons. Good use: find a photo or even drawing of the pose you want to use, it saves a lot of headache if you have the foundation correct. What’s even interesting to do is draw it from your head, then do another sketch from a reference photo. Bad use? Copying someone else’s picture and saying it’s yours. But! What is extremely helpful is copying drawings of old masters. Seriously. It’s worth a whole college level art course. And the old masters also copied other people’s paintings and such. Attribution and use are the deciding factor.
Dragons, what I’m currently working on, benefit from reference photos as well! Half of it does come from the imagination but even that part is based on images your mind has stored up or previously drawn.
Sorry for the lengthy answer but this is near and dear to my heart because of my own digital art adventures (read near failures). When I started using reference photos, the quality of my work changed. Dramatically.
I’m very curious to what anyone else thinks!
You do not have a soul. You have a body.
You are a soul. - C.S. Lewis