If you only use small amounts of milk, dry milk can be the way to go. Most milk powders mix in the same ratio, one part powder to four parts water. That means you can mix up a cup of milk using 1/4 cup of dry milk, or my favorite amount, a tablespoon of powder to 1/4 cup of water. Mix that up first, drop in three eggs and cinnamon to taste, and make about 6 slices of French toast (or, as it was called in medieval England, pan purdy).
As a side note, if you do have to drink the stuff, mix it up the day before and let it sit in the fridge overnight to dissolve more thoroughly.