Read the standards.. learn them and learn how to apply them to a live betta. Keep only bettas that meet or almost meet the standard and use them to breed. Join the IBC and get your bettas in shows... they may not win but no one is going to set IBC standards if no one is going to show their fish.
For instance your male has the wrong tail fin (caudal). It should slope downward and come to a point instead of being wide at the base. So in your fry you should look for fish that have pointed or nearly pointed caudals and use them in your F2.
This is Blue Jeans, he's one of my VT males and he has nearly perfect finnage by posted standards.
See how his caudal is pointed at the end? The dorsal fin should look like a flame almost.. BJs is a little narrow IMO.
Perfect your fish, get them to shows, generate interest and eventually VT will find its way back to popularity in shows.