First, I am no expert at DIY. I have "lucked out" and managed to find a couple of all day flavors that I like fairly quickly, so experimenting can take as much time as I feel like spending on any new flavor.
When I say add flavor I mean adding another one or two percent to an existing mix. Everyone has their own methods. Mine is based on patience! I mix a 5ml batch for a new flavor, let it steep the "old fashioned" way for a week or more, then test. If I add more flavor it's another week or more before I try it again. It is a sloooowwwwww process, but the one I use. I'm in no rush and have the time.
Steeping can also be done by adding some gentle heat. Another, really fast method, is to use an ultrasonic cleaner with a heater. Usually the temperatures used when heating are around 120 degrees, kind of hot to the skin but not really all that hot. Adding some shaking to the heating helps as well. Someone uses a game controller from a WiI, I think, to add some agitation. Conventional steeping usually takes at least a week and may take as long as a month depending on the flavors and percentages. Ultrasonic steeping might take a couple of hours. Steeping with heat and agitation can take as long as overnight. These are general times and everyone's times seem to vary according to taste.
Like I said, everyone has their own methods and techniques developed, usually, by trial and error. DIY is more of a hobby for most of us so that kind of works out fine. Above all, patience is a virtue with DIY.
