To be honest, there's no real "tutorial" to be made for it. There used to be much stricter guidelines. But I did some slop face-swap with a portrait and Tom Cribbs and it got through despite not looking much like the portrait.
Get a photo or graphic editor of choice, choose some portraits from the picker (you'll VIP/Free Trial to get access to the whole catalogue me thinks, but you can just save the ones you like there) and begin doing faceswaps. Take portrait or press shots from famous people, fighters, movie stills, whatever. Wanna take it a step further? Use a site like remove.bg to get a clean background removing tool and make your own custom backgrounds for it. gifs are allowed too so a good ol' waving flag is always popular.
Ultimately it depends more on how far you wanna take it. Wanna use AI? People already do, they just tend to be less popular. There's also something oddly nostalgic for the "slightly bad" ones.
Good edit example - https://mmatycoon.com/fighterprofilepublic.php?FID=70356
Nostalgic example - https://mmatycoon.com/fighterprofilepublic.php?FID=385007 (simply face overlay, skintone mismatching, which is somewhat nostalgic)
Custom example - https://mmatycoon.com/fighterprofilemanager.php?FID=409974 (gif background, no game portrait resemblance, etc.)
Faceswap example - https://mmatycoon.com/fighterprofilemanager.php?FID=410000 (done with an ingame portrait, face swap and a picture of Tom Cribb)
Hazard Bleak
"The KT org STRIKE! is no more. I had to find a new home. I'm undecided on which division I want to dominate, 170 or 185. So I'll start at 170, dominate, and then flex on 185. Be afraid, be very afraid. Just no nut huggin' hippies grabbin' my balls. You guys are gross!"