Tip for class 2 composites: wrap wedges with Teflon tape (plumber's tape) for better seal.

Like in this pic: https://ibb.co/YbdWfPQ

I don't do this routinely but only on cases where there is a gap between the gingival box and matrix band with the wedge. Especially for mesials of maxillary 1st molars with the mesial concavity. It really makes the wedge feel more snug/tight against the band. This helps ensure no overhangs, so no floss shredding.

I like keeping a small box with pre-cut Teflon tape to have ready for my assistant.