Erm i find its best to aim for trying to go over the front, you should then find a natural balance between being scared of face planting and trying to face plant.... some people call it the balance point. Its good to just practice up a curb or some small wall with no drop behind it. When you land try and get your weight over the front so you wheel sticks and you back risers, then you can let the brake of a little and roll to flat or attempt to huck the bike underneath you, and switch to back. As for hopping on the front. Again you need to be right over the front, and try and find the balance point, so you can hop using your legs to get the bike up, and your arms to place the bike. the higher you go, the easier it is, but also more chance of going over(which generally doesnt hurt as mucha s you would of thought).