Echo Gizmo, andyb and Les996 here.
Fact is, very few riders look far enough ahead. It takes a good bit of practice but is well worth it!
You should be looking as far up the road in front of you as you can possibly see (more difficult than it sounds!) while still watching the road conditions immediately in front of you.
If you know the road well, try and consider each turns entry / gear selection / corner speed / exit long before you get there. That way you as ready as you can be on arrival.
Things like trees over the road always worry me at this time of year. Wet leaves and dropped tree sap etc makes country roads a whole new ball game. I try and make a mental note if the conditions are bad on the way out so i'm ready for them on the way back!!
The advanced guys use reference points to help give the advantage eg. if you can see the way lamp-posts or telephone poles follow the line of the road but you can't see the tarmac due to hedges etc, this gives you an advantage before you get there. You want to be processing as much with your eyes as possible, each and every advantage you can get could make all the difference, it's also good fun!
Best advice I ever got was to consider yourself in a 360 degree fashion. Danger comes from all sides not just in front of you !!!! Always consider potential escape routes in every situation and ride with a margin for error just in case of the "unexpected" round that blind bend. NEVER EVER go at your limit all the time, you simply won't last long, no exceptions!!
The golden and first rule of biking is to get home after the ridings done!
Mart