Use a lockpick on a locked door or container
Move the pick left or right to find the sweet spot
Press the action key to set each tumbler when it rises quickly
Repeat until all tumblers are set before any fall back down
If a tumbler drops, adjust and try again
Use the Skeleton Key if you have it for easier picking
Increase Security skill to make lockpicking easier
Buy or find more lockpicks before attempting harder locks
Save before trying difficult locks
Practice on easier locks to improve timing