I'm just getting my paints together again (I haven't painted in so long about 50 tubs dried out), so seeing this is additional inspiration, one art schooler to another.
The only thing I would suggest is, not using black for washes. I think a much darker blue would work better for Cap, giving a better "shadow" appearance. Same thing for the white sections of his costume, maybe try a grey, or mix some off-whites with complementary colors to darken them up some.
Nice work! Can't wait to see more!
When creating a new thread asking rules questions, PLEASE make a relevant title! This will help down the line anytime anyone attempts to do a Search.
Note to self: "map" text = COURIER NEW
Always... no, no... never... forget to check your references.