[Question] "Soundproofing" a door?

I live in a house with a couple roommates and I wanna be able to play guitar without bothering them. The room is above the garage and is actually pretty isolated from the rest of the house. I think the only connecting area is the door. My amps are a Marshall DSL40C and a Boss Katana 100 (so nothing totally quiet) and at a moderate practice volume, the sound can be faintly heard from my roommates rooms.

From what I've researched, soundproof panels don't do much so I'm thinking of using weather stripping and a towel under the door as soundproofing. Is there anything else I should do?