I have used equal thickness plastic bread clips with success. I also had a 10X10 sheet of aluminum I bought at a hardware store for a different project. I just cut out a strip of aluminum, bent it double and glued it into place. Glue is key to both types of shims.

Pressing the clutch plate with one hand and the other hand held a pair of needle nose pliers with the 'shim' glued on both sides to slide the shim into place. It's not rocket science, you just want the clutch gap less than .020 inches so it will last a while.

I did have to raise the right side of the car a little to get better access, I don't remember if I took off the wheel so I probably didn't. Just the splash pan had to come down, which is a pain to get back on.
--
My back feels better when I sit in a Volvo seat