For this trick you should be comfortable with kickflips and frontside 180s. Roll fairly slowly at first, with your feet in a kickflip set up position - but place your back foot more over the heel edge of your tail. This will help with the rotation.
Crouch down to pop. You will need to get a fairly good pop on this to allow the board to flip. As this is a 180 flip, coil the opposite way to the way you will be frontside flipping, to help the rotation of the 180. You need to use more power than a normal 180 as you don't have your front foot to push it round (as it will be flipping the board).
As you rise up and pop, uncoil your body. By the tme the tail of the board hits the ground your upper body should be facing forward - so it's already rotated 90 degrees before you've left the ground. This is an indication of the power needed at the start of the frontside flip.
As you flip the board, kick your front foot out as your turning so that your front foot sort of goes out and round. Your legs should open as you're forcing the flip to go around 180. The trick is to try and leave your front foot off longer than a standard kickflip, to allow it to flip 180 without you catching it to early and preventing this. If you do catch these early, it's unlikely you'll get the 180 rotation.
If you're leaving your front foot off longer to allow for the flip, chances are you will catch the flip with your back foot. The more rotation you can get before the catch, the closer you are to your 180. At first you can catch and land 90, pivoting on the front wheels the remaining 90. If you have to use this method, try to get them properly of putting them down any sort of stairs, gap or ramp.
As usual, aim for the truck bolts for less chance of snapping boards. Bend your knees and beware of the board shooting out from under you as you land, it;s easy to put too much weight on your front (now at the back) foot after pushing it around 180. Once you've mastered these, go for the hardflip!
Check the video below - 2 angles to help figure the movement.
More trick tips here, with a whole host of new ones added soon.