See the index of Convenience Food posts here.
-- It's a hassle to pull out my food processor to make pie crusts, so when I made the crusts for the Christmas pies, I made a few extra and put them in the freezer. TIP: If you are having turkey for your holiday meal, make a crust for a turkey pot pie when you make the dessert pie crusts.
-- I know how to make bread by hand, but I use my breadmaker to save my wrists: I let it mix and knead the dough, then I put the dough in the bread pan, let it rise, and bake in the oven. I make bread mixes ahead: I measure the dry ingredients and store in labeled quart-size zip bags. There are labels on the bags with the ingredients to add, so I just pull out a bag, add the extras (water, shortening, honey, yeast) and turn the machine on. It also saves me from pulling out the cookbook every time I make bread. The bags are reuseable.
-- Cake mixes: take your favorite from-scratch cake recipe and mix the dry ingredients ahead, with a note or a label listing the items to add when you make the cake. There are plenty of recipes for cake mixes on the internet. My favorite chocolate cake is Hershey's Perfectly Chocolate Cake. (Link updated 05-2016.)
-- Ditto with your favorite brownie recipe.
What can you adapt to a make-ahead mix? Just about any favorite recipe. Don't add liquids, of course; I don't add shortening or oil either. I want a shelf-stable product, not something that will take up room in my refrigerator. Mix the dry ingredients and put in an airtight container of some sort: a canning jar or vacuum-packed bag are my choices. LABEL IT IMMEDIATELY; don't wait till tomorrow! Add a note inside or somehow attached with a list of the ingredients to be added, and any cooking/baking directions. I include the name of the cookbook and the page number of the original recipe.
If it's a new recipe, I make just one batch so we can taste-test it (and yes, I've found some we did not like). If it's a favorite recipe, I know we like it, so I can play around a bit with the preparation and packaging until I have it "just right". At that point, I can make as many as I wish to put on my pantry shelves for future meals. It's my version of once-a-month cooking.