Help Creating own bezel/overlays

[WedgeStar 0]

I was looking for a little info on where to start making my own overlays, I've googled a lot and I've found nothing. I have GIMP on mac that I've tried using to make them but it doesn't work out, black screen or way too small of overlay once I add them, I change sizes and thing just get distorted.  Any help would be greatly appreciated thank you.

[Beakerman 2]

What emulator/front end(s) are ya using?

[Vhero 1]

You tried youtube? Theres lot of video tutorials on there.