There are several common ways to open a lock, depending on the type of lock and available tools:

• Lock-picking: The most popular method involves using a tension wrench and a rake or even paper clips. The tension wrench is inserted into the lock and turned slightly in the direction the lock turns. Then the rake or a paper clip is used to push the pins inside the lock to the shear line while keeping tension on the wrench. When the pins are set correctly, the lock opens.

• Combination lock opening: For combination locks, the dial is turned clockwise several times stopping at the first number, then counterclockwise passing the first number to the second number, and finally clockwise to the third number. The shackle can then be pulled to open the lock.

• Shoelace or similar tools: For cars with vertical locks, a shoelace tied into a slipknot can be slipped between the door and frame to loop around and pull the lock open.

• Knife or butterknife: For simple locks (e.g., some bathroom doors), a thin knife or butterknife can be inserted and twisted or used to push back the bolt when there's enough space.

• Hairpins or bobby pins: These can also be used similarly to lock-picks to manipulate the pins inside a lock.

It is important to note these methods are for authorized access only. Illegal lock picking or tampering with locks is prohibited. If a specific type of lock or task is in mind, more detailed instructions can be provided. Would you like guidance on a particular lock type?