I couldn't use any of the commercially available ramps because my car is lowered and the ramp angles on all of them were too steep. Plus, making a simple one out of 2x12's was much cheaper. Cost me like $20 for one long piece of lumber that i cut into smaller pieces.
A 2x12 works well as the 12 is wide enough plank for the entire wheel to fit comfortably on it, and the 2 (actually 1.5 inches high) is low enough for my lip to clear (barely), which is 2.5 inches off the ground. So when the wheel hits each 1.5 inch step, there needs to be enough clearance between the tire and front of the lip (distance from tire to lip is around 14"-17") to clear it.
To be conservative, each step should be 18" apart to insure the front of the lip will clear the next step. HOWEVER... I got cheap and I made each step ~14" apart so that i could make the ramp out of two 2x12x12 (had only tiny slivers of wood left over after cutting out the steps). So...
top-step: 14"
2nd step : 28"
3rd step : 42"
bottom step : 56"
Had I gone with each step being 18" apart, the base step would have been 72" long (6 feet!!) and i would have had to gone to using two pieces of 2x12x16, which is a little more. Plus it would have been a lot heavier to lug around.
Anyways, my procedure is this:
1) Drive up the 4-step ramp till car is high enough to slip the floor jack under the front of the car
2) Center the floor jack so that the contact spot is just before the oil drain pan flap.
3) The 4-step ramp gives me just enough clearance so that i can jack the car up high enough so that i can slip jack stands under both sides of the front of the car, and rest the front of the car on the two jack stands.
$20 of lumber, a saw, a hammer, and some nails
