Past about 40 yards depth perception becomes pretty inaccurate. About all you can do is get a precise landing routine going where you know the timing. On the landing hot issue, have you learned how to crab your plane? That's where you roll it one way and rudder it the other, making it fly straight with the wings tilted a bit. It kills some lift without increasing airspeed which will let you have a steeper approach than normal.

Here are a couple of videos of it. The first is a model where the crab (or sideslip as some call it) is pretty extreme, the other is a full scale plane where it's much more subtle. In both though, the approach is done without the wings level and the rudder is being used to make the plane come in straight.

http://www.youtube.com/watch?v=wW8GRJI6Kz4

http://www.youtube.com/watch?v=9fTS-fKX13U