When there are no special circumstances, like huge competition with more total capacity then demand, I usually adjust my prices according to loadfactor. If loadfactor gets too low, I drop my prices 5-15%, if it gets too high (usually more then 90%), I raise them by 5-15%. I usually check all my routes every couple (real) days.
If there's something special about the route, for example overcapacity or something like that, I tend to go for 10-15% below standard pricing and leave it there.
If I can't get decent LFs, I usually dismiss the route in the long run.