You do your research, you look at tons of "profiles" and pictures or you have someone do that for you like a matchmaker. We have been lucky to find a great one, I emailed her all our little things we look for and look to avoid and she would point them out when we look at houses.
You figure out your dealbreakers and your "can live withs". For us, the dealbreaker is space and openness(much like height was for me in dating--hey I am a tall girl and I don't live in flats!). It is really important that our house feel open and have space--we want to always be a part of the action even when we are in the kitchen. We also want space for all our stuff--our living room has become toy central and there is nowhere else to put it--in fact we have a storage unit and use Elle's room as a storage stash(because she is too young to care). We are learning things we can live with as we start to look at houses.
We are finding in our area, alot of short sales. Which we are learning are anything but "short" timeline wise. It must be due to the oil and gas boom and bust cycles in our area.
I guess we continue to date around awhile before we really find "the one." We are definitely ready to settle down and spread out, so wish us luck!