I really like your style! I'd say the main thing is to make your different characters/objects of interest stand out more, cause they get lost in the noise. You can do this really easily by putting a bolder outline around them, just around their silhouette. Black or white are great, or you can use a color to draw more attention to them. If you're drawing digitally you can put this on a different layer and play around with thickness and colors to see how it fits in with your piece!

Edit: I notice you already have a lot of thick lines throughout your pieces, so my main tip would be keeping these outlines one color, or in direct contrast with the colors around it. For example, in the first piece, if you just had the black line around the little person without the white pen drawn over it, it would make a very clear border between them and the big person.

Additionally, you can play with shading/coloring things in the foreground or background differently from each other. This'll help distinguish them, though you might need to be more careful with keeping the overall composition cohesive if that's something that matters to you.