In what way can I improve my paint job ?

I'm making my first Eva Foam prop, a Katana (To cosplay Sesshomaru)

I first used scraps to make a training piece. So far, I like the shape but my paint job is not looking good. How can I improve it ? Can you spot my mistakes?

I primed the foam with Tacky glue. I used silver acrylic spray paint (On top of other layers of paints. Because it's a training piece I already painted it several times to train). For the lighter part I mixed the silver spray paint with white paint