*The advantage of using a shower cap when baking yeast dough is that, unlike plastic wrap or a tea towel, the shower cap allows the dough/yeast to work with the warm air, keeping the dough moist in just the right way.
Plastic wrap is a good alternative to a shower cap, though it doesn't provide the same conditions for the dough, but it is much better than a tea towel.
Tea towels are very good for the second rise, when the rolls or bread are shaped, and we now want the dough to dry out a bit on the surface, as opposed to before when we wanted to retain moisture in the dough.
** If the rolls are brushed too early, there's a risk that the egg will form a layer of scrambled egg on top of your rolls.
*** Bake only one tray of rolls at a time and place the baking tray on the bottom rack.