If it's a physical "ugliness" issue, double-down on existing efforts to reduce obesity and unhealthy lifestyles, and for everything else, easier (subsidized?) access to plastic surgery will definitely help. Of course, talking about plastic surgery is premature when the country can't even guarantee affordable access to life-critical healthcare, so that has to be solved too.
Poverty is also a major problem that should be addressed (for many other reasons beyond young men's dating prospects) and would make all the other problems easier to solve.
It would be pretty difficult I think without some mandatory "relationships" education being implemented or something, which is a little too totalitarian for modern democracy I'd think.