IMO, the best way to get them to breed is, buy a 125G, plant it very heavily(with easy plants) and allow the male and females to interact with each other as they wish. provide caves and tunnels for the females to hide if they choose to run.
This is an extreme situation, and one I would think almost noone carry out(except me lol, love bettas)... This situation allows the two sexes to interact as they please, not when a third party decides it's time.
What size is your current tank???
If under 50G, it doesnt allow the female or the male to retreat anywhere should they not want to mate...
Again, plant your tank very well, with one real floating plant too(can I suggest Giant cardamine).