This method doesn't require much skill or practice to get right. If you do make a mistake, well, if you have enough hair on your head to wear a mohican, it will grow out soon, so don't sweat it.
Step 1: Equipment
Electric clippers are much more effective at removing hair than scissors, especially when you can't see what you are doing.
If you want to shave all the way down to your scalp, you will need an electric razor. The trimmer should be a sturdy slide-out design, and NOT a flip-out trimmer that is too flimsy or too awkward to use when you can't see what you are doing.
You will want to do this in front of a mirror! An additional hand mirror will allow you to check your work in the back, but you won't be able to hang onto it while you are trimming. The beauty of this method is that you are doing it mostly by feel.
Lastly, you need hair. As long as your middle of your hairline is somewhat forward of the top of your head, you can even have a huge forehead like mine.
Step 2: Tape
Pat your hair as flat as you can, brushing the top forward, and the back downward.
Center the tape between your eyebrows. Then pull it straight back, over your head, to the center of your neck.
Use the hand mirror or an honest pal to determine if the tape is centered on the top and the back. Pull it off and recenter it if something doesn't look right or feel right.
Step 3: Oil
Next, we cut!
Step 4: Clip
Then clip from the nape of your neck upward, closer to the center each stroke. You won't be able to see it, so use your other hand to make sure you're not getting too close to the tape.
When you do get close to the tape, feel along the edge and press it down as you clip, to ensure the clippers do not slip under the tape. Run the clippers along your fingers and then reposition them. Use short strokes and keep the clippers pointed straight back or straight forward.
Try not to nick the long hairs sticking out sideways (they are part of your mohawk).
Step 5: Other Side
Step 6: Remove Tape
Step 7: Optional: Touch Up
The technique here is to make an L with your other hand. Smooth a section of your mohawk sideways, until your index finger is just barely covering the edge of the mohawk. Then run the trimmer/razor along your finger, taking care not to run it off the end of your finger.
Your razor's design will determine the proper position for your hand. Keep feeling around for sections of stubble that need shaved, and use your other hand to protect your mohawk.
It is easy to miss stubble near your crown or on the back of your head. Patience and practice, and checking with a hand mirror or a pal will enable you to get it all. If you don't, your mohawk will probably cover it up until it grows out in a day or two anyway. Don't get impatient or wild with the razor! That's how you get a sawtooth mohawk.
Step 8: Clean Up!
Step 9: Looking Good
Now you are ready for a punk show, or a Gigantes game, OR the Apocalypse. Enjoy your Foolproof Mohican!