Educate yourself on the way various systems in the home work. Don't rely entirely on the home inspector. Look at the way things are laid out and work and ask yourself if it is the way you would do it if you were building the home.
It's unbelievable how annoying little things can be when you take them for granted and don't consider the ramifications on how they are done. Examples: out side water spigot placement, back and side yard access with vehicles for landscaping, trailers etc. down spout locations are important to look at too. You could be inviting all kinds of foundation issues if the down spouts drain too close to the home.
Drain condition is another to consider especially if its on a slab, poor water pressure or slow drains here can get extremely expensive because in most cases you gotta bust up concrete to make repairs.