Rough terrain is usually uninhabited and, therefore, unlit and difficult to see. And if objects come between you and the runway lights during final approach, they are probably branches. Fowler suggests, as a touchdown target, a point on the runway at about the third set of runway lights. You should cross the threshold at a minimum of 100 feet. The FAA's Flight Training Handbook offers good advice on how to determine the roundout point.
Fowler suggests having a go-around point in mind to avoid running off the end.
First of all, you would hope to be over or within gliding distance of an airport. Most computerized flight-planning programs allow you to select a string of airports as your route to your destination and will calculate the headings to each. Gliding distance will be improved, of course, by high cruise altitudes. That reduces the odds of an off-airport landing and simplifies the search, should one be required. You also want to avoid rough terrain when flying cross-country at night.