Do a 180 on a Bike

A 180 is a half spin of a 360. It is done when the rider bunny hops and lands the spin.

Steps

You should start slow at first and as you boost higher and spin faster you can increase your speeds.
Crouch into the bronco stance.
Just before you bronco, twist your head 180 (look at the ground slightly behind you). And twist your handlebars to do a 90.
Pull up your front then flick your back end of the bike out(you may want to bail but stay on the pedals and you will land it).
Let your legs and body twist with the bike.
Land pedaling in the opposite direction, and fakie out(or do a rollout) .

For more advanced riders, you can land the 180 on your back wheel with your BACK BREAKS PULLED IN, and use your motion to spin and do another 180. This looks like an awesome 360 when its done correctly and smoothly.

Always remember to look backwards in the direction of the turn
It's easy to practice doing this off a low curb at first--ride parallel with the curb and 180 a little to the side and off the curb.
Also some may find it easy to learn/practice it on a very tall and wide tabletop
If you are a beginner at this trick, hop as low as needed.
If on ground you must bunny hop 6'inch or higher

Landing while sitting down is not advised for males.
And turning as much as you can on the ground to limit your airtime spin helps a lot.
The most common mistake at landing is landing crooked and losing your balance, and then you can't ride away with it.