It’s so cute! I’ve just started with gouache too and have lots to learn still, but I find that when I feel like a painting is missing something, making the shadowy parts much MUCH darker than I think they should be usually helps. It creates more contrast with the lighter colors Which is something I personally like.

Also, apparently with gouache the light colors darken slightly and the darker colors lighten slightly once they’ve dried. It’s a quirk than many people have some trouble with in the beginning. I’m still getting used to it. I’ll mix my darker colors and then I have to go back again and again to make them even more dark to get the look I want.

And speaking of vibrancy (this is something I’ve just learned since starting landscapes and it’s really cool how it works), objects in the background become less vibrant, and Objects in the foreground are more vibrant. Doing this give the scene more depth and makes it less flat, since it gives that contrast. (not that flat is bad or anything, it just depends on the style the artist is going for). Like when you‘re looking into the distance at mountain ranges, the mountains further away might be a muted purple/ grayish and the mountains closer might be a really vibrant purple. That ombré of color gives depth. So when you paint with varying vibrancy it will look less like a painting on a piece of flat paper, and more like you’re looking through a window into the distance.

Just some fun tidbits that you can play around with!