Be generous to people other than your girlfriend/wife to demonstrate a high value. I think a lot of guys try to be really generous to their SO and it backfires on them by making them look like a total chump and very beta. BUT doing something generous for someone else (think charity, helping a family member, giving a $20 to a homeless guy, etc) is a great way to create a big attraction in a very alpha way.

Basically: being generous to SO = beta, being generous to others = alpha.