Eggrolls are easy to think of in two steps. First, think of the wrappers. These are really not that hard to make by hand, but they are *super* time consuming. I would honestly recommend just getting your eggroll wrappers from a grocery store or Asian market, because the ones you make by hand are not any different, and it adds a lot of work to the eggroll preparations without really adding any benefit.
So, assuming you're smarter than me and you buy some eggroll wrappers, you need only to consider what you want in your eggrolls.
What are your favorite kinds of eggrolls?
Trivia: Wood ear mushrooms are named because, when growing, they look like ears sprouting out of their host trees.