Helmet padding

What is the best kind of padding for the interior of your helmet. I have some leather cross straps inside the top of the helmet but nothing on the cheek guards or the back of the helmet so it tends to bob a bit. The thing is I kind of live in a very warm and humid climate so any suggestions on how to better secure the helmet(minus a chin strap of course) without cooking me inside my helmet lol?

Foam works in all honesty your lid isn't going to breath it will be hot regardless what you do

I went to Hobby Lobby and bought two big pieces of foam. One was an inch thick, and the other was two inches thick. I cut them to the sizes I needed, and then I used that double-sided foam tape to secure them inside my bucket (I had it laying around; I'm sure any adhesive/Velcro would work fine). The foam is really cheap, and if you take your time cutting it, it can look pretty nice inside the helmet as well (I know no one else sees that, but I do, and it'd bug me to no end if it looked shoddy).

This is what I use in my lid Ballistic Helmet Pads | SKYDEX you can get them on the bay for a fairly good price I think I paid $45 for mine. My lid sits nice and snug and when I do sweat I can rip the pads out and through them in the wash.

My old helmet had foam padding from AC Moore, with fabric wrapped around em like little pillows so the fibers from the foam wouldn't shred and get all in my hair. I was in a hurry to finish my Sgt Fang before Halloween, so I glued the adjustable headband-cradle type thingie that I had pulled out of a Hasbro Darth Vader. It actually works really well. The plastic is a little uncomfortable after a long time, but I don't worry that it's collecting sweat like the foam did.

Don't use the styrofoam you've got lying around from the packaging of costume pieces you've recently gotten in the mail! You will realize immediately that the echo of crunching styrofoam drowns out every other sound and slowly drives you insane.... crunch crunch crunch "what? huh? I can't hear you!" crunch crunch crunch...