You will need the following:
-Hearing protectors(Probably can get a pair for less than 10$?) I also advice you to buy ones that are can be folded for travel and also have removable ear muffs
-On ear headphones(I used some old broken sennheiser px200's)
-Soldering iron(if you have to fix broken headphones to save money)
Step 1: Step 1
If you have ones that do have the removable ear muffs you have a head start. All you have to do is separate those ear muffs off from the case. Then you have to click your headphones free from the frame. This leaves you with only the headphones themselves without any frame. Then you have to add some hot glue to the bottom of your headphones(the backside) and then attach them to the middle of the hearing protectors. Then just attach the ear muffs back to the hearing protectors the way that the cord goes in between the ear muffs and the hearing protectors. This gives your headphones a sleek look.
If you have ones that do not have removable ear muffs you have two choices. Either stuff those headphones in there with force and leave the cord going on top of the ear muffs or then do some handy craft by cutting the ear muffs and then sewing them back in to shape after you've made the cord go under the ear muffs. Anyway all you have to do is to take the headphones free from the frame. Put some hot glue to the back of them and stuff them in to the hearing protectors.