"KIS" I do a lot of PP and I just use a pin or just hold it in place. fabric pieces for PP are bigger than the area to be covered and I always oversize the pieces a bit more than necessary and trim after the section is done. I love PP.
peace

Missouri Star Quilt Co sell a fabric glue stick that works. Thats what they used in their tutorial that is online.

If I need a piece of fabric held in place for PPing I just use long basting stitches on the machine.

I have had glue, but don't like the residue.
Also, have sometimes used painters tape folded over to hold in place.

Carol Doak always says, PINS are your friends!

I just use a pin to hold the first piece and finger press each piece after that

Masking tape or painters tape. Just dont put it on the line you will sew next. This is my method for every piece and keeps the.piece smoother than pins. Easer to work with

old school here, pins, never use glue on a quilt...
katz