One thing I know (from genetics at least in mammals) is that unless you can get the family line back to about 3-4 generations you can have any mix or anything. Like your boy or girl could be the odd ball from their parents but you wouldn't know until you saw what type of babies they produced.
If you aren't planning on making a business than defiantly experiment (obviously while keeping the betta's health in mind). It takes about 3.5-4 months for a betta to mature and so you can continue to 'play' with genetics within a short time frame.
I know its favorable for some people to breed father with daughter or son with mother or even brother to sister. The idea is to draw the line more together than apart. BUT If you're not trying to pin point a specific type of betta than make sure that you maybe take your one male and then your one female and do 'test runs' to see what type of babies they make.
I just decided to make a little chart although they are very basic it was a way to express my idea lol
It's not something to completely go by since i have never bred bettas before and am now just looking into maybe doing it in a couple of months. So I wouldn't say take my chart and fly but the idea of genetics is the same for almost everything. Only when we're involved and we're breeding for things that we want the genetic table changes because we go for more unnatural things that may or may not help the animal verses nature when it goes for similarity.