Only pick lock your own locks. DO NOT pick anyone else's.
Get two paper clips
Find a lock
Bend one of the paper clips so that it is bent at 90 degrees
Lengthen out the other paper clip into a straight line
Find out which way your lock turns. This one turns in a clockwise direction.
Insert the hooked paper clip into the lock. Apply downwards pressure and pull it in the direction the lock turns
You MUST keep the pressure on that paper clip the whole time. Failure to do so will result in the lock not turning.
Insert the straightened paper clip into the gap made by the hooked one. Make sure it is pushed all the way to the back of the lock
A lock consists of pins that prevent it from turning. When a key is inserted, the grooves in the key will push the pins up. When all the pins are pushed up, the lock can turn
To push all the pins up, lift the straightened paper clip up and "rake" it towards you. You will hear the pins clicking. You will know when you have picked the lock when the hooked clip turns easily.
It will be likely that you will not succeed on your first try. Keep trying until you get it. Practice makes perfect!