Step 1: What You Need
You will need a plank of wood that is quite strong (Doesn't matter how wide just wide enough so you can bike up it), some bricks or some wood, and 2 rolls of Duct tape or so.
Step 2: Step 1: Making the Ramp Base
All you will need to do is tape up 5 layers of bricks, 2 bricks wide. You need to tape it strongly. You don't necessarily have to use bricks, you could use wood blocks etc. I used a some wood and some bricks in the base.
Step 3: Decorating the Ramp
You can do what you want to your ramp, you could put Go Faster stripes on it using permanent marker.
Step 4: Connecting the Ramp With the Base
Just tape the ramp to the base but reinforce it. It should keep it stable just the bit more.
Step 5: Enjoying the Ramp
Finally you have just got to enjoy using the ramp.