A well known one is the egg shot glitch, where if you go next to a thin tile and ride it up, you can go through for instance, a fountain.
The gun swap glitch, i see people do this to lessen reload times. If you swap from any gun, for example a high reload gun like Souizen to a low reload gun such as smgpk back and forth very fast, you can spam the souizen, and as it gets low, you can clock the grab button to reload and it uses the reload speed for smgpk on souizen.
If i find more i'll post them ^_^
Oh, the superfart- fence thing. If you go to the bottom of a rare shop fence and superfart while pressing up you can get through the fence.