If you are playing St Andrews, you can not help but end up in the fescue. Fescue for those unfamilar with it is the worst form of rough. Impossible to hit out of without using punch shot. Hitting distances are impossible to judge beyond 30-40% fescue. It ruins your hole. It ruins your round. It ruins your St Andrews experience.
I find myself playing St Andrews a lot because the forgiving fairways and huge greens make it relatively easy to shoot under par. Unless you tango in the fescue then all bets are off.
I find that drives that hook slightly to the left on #9 and #10, two straight, short birdie holes, end up in the fescue. Other holes have vast amounts of fescue lurking just off the fairways. Straight drives and not trying to overdrive fairways is the key. Avoid the fescue!