Okay! Now that step is done and the black paint is dry, over top I like to add very subtle hints of silver to show the raw metal exposed as if paint was worn away. I used the silver metallic paint pen for this step.
You definitely don't want any solid silver lines, but more broken up dots, dashes and chips. I'll also put in a couple cuts in the paint job with some broken, natural lines. Work with the natural texture of the EVA Foam too! If there are divots or holes, you can define them even more. I will often use my Dremmel to actually create scars and lines in the foam, which you can then outline in silver.
Here's a few nice scratches and scars I put in for some flavor
NOTE: This is an EXTREMELY time-consuming process so take your time and be patient! I find that if your foam crafting isn't that good (I'm still improving mine, personally), a good paint job can save a piece and make it look fantastic! If you make any mistakes in building your armor or cutting, you can embellish them and make it look like "natural weathering" too. I use this a lot when I cut too far into my foam with my box cutter lol.