Never really thought about it that much. I always make mine really potent. My butter is a pound of frosty trim to a pound of butter. I like to be able to use smaller amounts of active butter. After the butter is done and strained I put it in an ice cube tray. This makes it easy to use.
I did a boiling water/butter extractions in the past but now I prefer to grind all the trim really fine and cook the butter on low heat. At a certain point before it begins to brown I turn off the heat. I allow it to cool and use a bur mixer, some water, and a dash of cream to re-emulsify the butter. Then I run it through some cheese cloth and a fine mesh sieve.
This new method has proven VERY effective.
I'll have to think more about dosage consistency though, I usually just assume my edibles will get me really stoned for a long time. But I bet if I used different quantities of active butter I could control dosage pretty accurately. Make cookies and label them: High, Higher, Highest, and Waaay Stoned.
Thanks guys!