Iamstretchypanda, no need to “add and pray” - we can find out what concentration of experimones/putatives you need from such factors as: how many sprays of the final product you’d like to apply in one go, the number of elements in your mix, etc…
If you start with the ideal mix you’d like and work backwards, then you can figure out the best order to make. Even if you have a rather dilute phero-per-spray mix that you want to beef up, it can be worked out.
An important variable is how many elements you are planning to get in the final mix. The more elements, the more concentatred each has to be… OMG the initial expense rises like in two dimensions, heck… but you still get a number of strong mixes that will last you ages, so it all works out in the end, like buying in bulk 
Suppose you had 100mcg/spray bottles of 10 pheros. The simplest mix of all them would be 1:1:1:1:1:1:1:1:1:1, I guess, and they’d all dilute each other to the extent that a spray would deliver 10mcg of phero A, 10 of phero B… etc. If you only used 5 in a mix then you’d get 20mcg of each. Pretty hefty if one of those 5 is -none or something like that.
Now that’d be a good spray!
Your mix would last you ages, as would the source bottles. 10 bottles of experimone whatevers at that concentration would be quite an outlay, but it would deliver the same pheros and probably would in the long run be far more cost effective than buying the 5mcg bottles and the like - I haven’t done the sums on that yet…
So Mark’s 30mcg concentration is a good general purpose mix that will give you (assuming equal measures) a 6-phero mix of 5mcg each of pheros A-F. With one spray. Two sprays is a good old dose! A 3-phero mix would dispense 20mcg of pheros A-C…
I am thinking up ideas for mixes based on combos that I have enjoyed, and the desire to make them to-go and portable, but this is largely theoretical at the moment, I cannot really treat myself to any delicious concentrated experimones for a bit until maybe Christmas or so, I do have plenty of good stuff in my arsenal already but I’m going to have to do the “drench-myself-in-it” thing should I make a mix. It is a small price to pay for portability though. And the same pheros get applied at the end of the day whether I spray them at home from individual bottles in a combo, or mixed in a to-go.
So I’ll be pleased to help if I can, I’m very interested in the mixology thing at the minute, I’ll be making some er, fantasy mixes as well as some real ones, until I get some nice concentrated experimones.