Wear safety equipment. You are going to fall when you start out, and a set of pads will make this a lot less uncomfortable.
First, you need to learn how to stand on the deck. Try walking up a set of stairs: the first foot you step up with is your dominant foot. Most of your moves will be done with your back foot, so this should be your dominant foot. Place this foot over the rear of the deck, behind the rear truck. If you're using your right foot for the rear, this is a normal stance, and if you're using the left foot, you're in a goofy stance. Despite the name, these are otherwise identical. Place your front foot on the skateboard parallel to the edge of the deck, with the ball of your foot over the front truck. Bend your knees a little: this will help you absorb bumps and makes it easier to bail.
To move, balance on the board with one foot and kick with the other. Most skateboarders kick with their back foot, but a few switch between this and "mongo foot," which is kicking with the front foot. Some beginners find this easier to do, but setting up for tricks is more difficult.
To make sharp turns, you'll need to perform a kick turn.
Lean on your back foot until the front of the skateboard comes off the ground and tilt in the direction you want to go. This way you are rotating only the back wheels. Put the front wheels back on the ground when you're pointed where you want to go.
There are two ways to stop: you can set a foot on the pavement and drag yourself to a stop, or you can tilt your skateboard back and let the edge of your back foot drag.
Posted 3625 day ago