lips

Use a lighter touch. The gasket seal of your lips and tongue on the face of the harmonica work best when they're soft and supple. This is especially important when you perform tongue block techniques like the pull... with the slightest amount of pressure you should be able to close all of the holes in your embouchure for the start of the pull. This also helps when sliding on the harmonica... you're quicker and will have less abrasion due to the tongue and lips gliding across the face of the harmonica, not getting stuck in the holes as you move.

A light touch of your lips and tongue on the face of the harmonica are essential for the proper execution of technique and to achieve good tone. If your tongue, lips or corners of your mouth become tender and painful, then you're pushing too hard.