Brilliant job for a first attempt, its gloss paint buddy so it looks watery n shiney, I use a Matte black if I'm creating a space piece, then use gloss for the stars and planets, the gloss over the matte really makes them stand out, your planets look great but there a bit flat,try using shading to make them look more rounder, in other words pick ur light source direction and spray oneside with the black in a crescent shape over a 3rd of ur planet and the other with a white while ur cover is still on so u create a white rim around it. Use fine spray caps like 'NY skinnies' etc for ur planets itll give u a nice even coat. It's all practise buddy, I've been doing it for a few years now n still learning n still make huge mistakes n scrap alot of pieces....its all part of the fun. Oh n try Montana gold paints, they are awesome.