Having tried to do my mixing experiments with both q-tips and an eye dropper and even a calibrated plastic beaker, I would suggest a more accurate and more satisfactory method.

Get yourself a small (1/4-1/2 tsp size) stainless steel measuring spoon. It is both more accurate than drops off a q-tip and easier to clean than plastic. After each dip of paint swish it around in some mineral spirits and wipe it off with a paper towel. I used my wifes stainless steel measuring spoon set from the kitchen, but mums the word on that.