Fake Muscle Shirt Shop Superhero Costume. HELP!?

Superhero costume. HELP!? - fake muscle shirt shop

I went out like a super hero for Halloween and have fun using ideas on how.
I wanted to falsifying the muscles (the T-shirt thing), a band around the head, leg, and who knows what else to use ..

What kind of shirt? What kind of accessories? and underwear on the outside?

Im not a superhero specific ..
In a simple random sample is