So here's what you do. Head down a road that ends with a building straight on with a sidewalk just in front, and when you are about 2 seconds before the building, lean backwards on your NRG, then as you hit the curve, lean forwards. You will now the launched about 3-4 feet into the air, still having the same speed forwards. This will be very helpful if you want to wallride up a building. Also good for using bumps. If the bump is "too high" to stunt on, just use this trick and it will be stuntable. Also, if you want to do some grinding, just hit the curve with an angle, and it will give you a good spin, so that you can land on the rail.
Off-Topic.
If you lean back as much as possible on the NRG, so that the back frame of it is in the ground, lean forwards as if you were speeding down a road to get that extra speed. If done correctly, you will get kicked into the air, good for the same stuff as the pre-mentioned trick.
Good luck!