Breeding bettas - ATTN queenpixie

Ooooh, that is a good question...Always breed the best you can afford (in any breed really) Go to reputable breeder and select a nice pair...Some strains are much harder to work with, so you are better off to start with something easier even if it isnt your first colour choice.

Always know the genetics of your fish...A breeder can tell you what to expect from your pair-ideally a brother and sister. Randomly choosing two fish (lets assume heritage unknown) could result in a spawn of relatively "grade fish"...Good as pets, but not much else...Raising Betta fry is EXTREMELY time consuming, so if you are going to do it, better to do it with something that will net (pardon the pun) a few bucks...

Outcrossing different strains is a whole other issue....It can take 4 or 5 generations to see the results you are looking for, or perhaps never obtain that result...Best left to the hardcores...

Oh and lets not forget genotypes and phenotypes lol...Another piece of information you can only obtain from the person that bred your fish.
Fish donot have to necessarily "display the trait" to carry it...Two rather average fish, could produce the ideal HM, but the chances are better if you start with 2 HMs that display the trait, not just carry it.

I hope that has sheds a little light on things...Betta genetics is a very broad topic and no something that can be summed up easily in one post...