A professional lock-picking tool is essential for any professional or aspiring locksmith. With a few different tools you can pick most locks and avoid the need to call a locksmith in a crisis. The best lock pick sets will have a variety of different tools that can handle the majority of pin tumbler locks, warded and wafer locks. They will also include a single pin pick which moves one pin at a time, a hook pick which has a hook shape and is used to move a pin into a space and a half ball or full ball pick which takes the broken off key out of a lock.
There are several companies that make high quality and affordable lock picking tools. The more expensive ones are usually made from better materials and will last longer. Cheaper sets are often fine for beginners or as a starter set but most people will eventually upgrade to something better.
The Art of Lock Picking: A Look at Essential Lock Pick Tools and Techniques
Generally you will want to look for sets that are titanized. This process adds an extra layer of metal to the tools which makes them more durable and reduces friction. These are more expensive but worth the investment.
SouthOrd is a company that has been making picks for decades. Their tools are typically less expensive than Peterson or multipick and still perform well. They offer a variety of single pin and hook picks, as well as a rake. They also have a fixed tension tool which works very well on flat bottom locks.