Use your lockpick on the door of the healer's hut just outside the town. Train your Pick Locks skill to about 40.
Then, you can safely use your lockpick on yourself (i..e, pick your nose) to improve you lockpick skill. If you tried that with less than 40 in Pick Locks, you could kill yourself.
Picking your nose would NOT be able to raise your Pick Locks over 91 or 92. After that, you would need to lockpick the houses in the town to get the skill up to 100, the maximum in the first game. Try picking the doors on the same screen as the tavern, (the butcher's and baker's doors with the notes posted on them,) the door at the end of the street, and the two doors in the next screen to the right, (the sheriff's home and the dry good store.) Try moving and switching around when you are lockpicking those doors, (i.e., pick a door, and then the next door, and then the third door, and then go back to the first door, etc..) If you repeatedly pick the same door too many times, the sheriff will arrest you.