I started keeping my baking powder in a baggie a year to prevent clumping. Works like a charm.
Then add the second ingredient until you've hit the proper measurement amount.
Voila. Easy measuring, fewer dirty dishes. I even cracked the egg into this for one less dirty dish.
Speaking of eggs, what do you do with your egg shells? Garbage disposal? Compost? Trash bin? Window sill?
I keep all of my egg shells in an open container on the window sill so that they can dry. Periodically I crush them with a meat mallet when the container gets unwieldy. Don't put a lid on the container or the moisture from the shells will mildew and mold. Believe me, I know.