I don't think I'll make a good navamsa astrologer
, since I'm not married yet. So, what makes a good navamsa chart? To me marriage is all about giving up pleasures for the sake of another, a new life that takes birth requires all your attention, so marriage is a sacrifice and about giving up pleasures- that you dedicate your life for the benefit of your spouse and children. This is called higher-pleasure of life, only few good souls are able to wield it's full power.
RV Ramanan has written a good article on Navamsa combinations, I suggest you go through it.viewtopic.php?f=18&t=6870