I now use the little clear plastic cups pills are dispensed in in hospitals for measuring small batches. They have lines on the sides that I mark using a black Sharpe so I can see the marks when I hold the cup up to the light as I add fluid. I can get a proper mix of amounts as small as a teaspoon full using them. I purchase them from Amazon by the hundred for about 10 cents each.
I do this because I end up using the tiny batches of epoxy to repair all sorts of things, including commercially built and well-used kayaks.

For Your Information,
John VB