Is it safe to assume that I can hand mix powdered ingredients and get an even amount of dispersal? For example:

15g ginger
15g guarana
15g bitter orange
150mg yohimbine

If one serving is a total of 1505mg is it safe to assume that within that serving is:

500mg ginger
500mg guarana
500mg bitter orange
5mg yohimbine

Are there various dried extracts that will not hand mix with other dired extracts?

Are you talking about capping, making a suspension, or adding to a liquid? It sounds like you're just gonna mix it all together and drink it, which is coo. Provided that you shake it up very well, you should be able to get a pretty even mixture. There may be a couple "hot spots," but aside from the yohimbine, that shouldn't matter too much.

I would make sure to give it a good shaking before each time you use it, to avoid any settling that may occur.

I do this often.

A few things:

-Shake it - upside down - on a regular basis. Some ingredients will have a tendency to settle on the top, shaking it upside down helps with this.

-The mixture won't be perfect and there will be hot spots. For this reason I don't add ingredients if they are going to make up less than 1% of the entire mixture, especially if it is an ingredient I don't want to overdose on. I would come up with an alternate method of using the yohimbine.

-Some ingredients don't mix too well, but you can usually get an even mixture. Ingredients that tend to clump in my experience are alpha lipoic acid, carnitine, and caffeine. My caffeine might not be any good though, I got it some time ago. If there is an ingredient that is not mixing well you will usually be able to tell by the difference in color. But, most of the time you get a good mix, herbal extracts seem to work well.