Hi, Sophie. Here is me trying to be more active on this here forum. (＾▽＾)
Your perspective is usually pretty good, your practice seems to be paying off, though you still seem to have a problem with the perspective of organic subjects.
I wonder how often you use reference for creative work, personally, after seeing a lot of artists seemingly working without reference, I tried for years to draw purely from imagination; lately I've begun to think that working without reference isn't realistic, some people can do it, some can't... maybe. (;n;) Those artists who don't use reference all seem to draw a basic character with only the hair and clothes etc. to differentiate them. I also wonder if you've ever heard of Jeffrey Watts of the Watts Atelier, the atelier has a youtube channel with some decent painting demonstrations, along with those of guest artists like Eric Gist. Watts and Gist, both professional illustrators, have mentioned that they never really work without reference, and it's been said a lot that if using reference was good enough for artists like Andrew Loomis, J. C. Leyendecker, and Dean Cornwell; and Michelangelo (°◇°), it's easily good enough for us.
Texture is another hard one, both in terms of getting the values right and finding digital brushes that will actual put down something convincing. As far as I know, texture depends mainly on the "edges" or transitions between the values, and the hardness or softness of the lines.
Your paintings seem to lack a broad range of values, they kind of blend into a middle value all over. I'd suggest thinking more about separating the subjects into "side plane" and "front plane," and think about the contrast over the entire image, as well as the contrast within each object in the painting. I find comparing the contrast between values to work a lot better than trying to look at the values and copy them exactly 'right.'
Anyways, there's what I got for now, see if you can get some use out of it.
Are those green guys with the big teeth self-portraits? :-P (^_-)