The goal of picking a pin tumbler lock is to lift the pins to the same heights that the key would allowing the lock to open. The number of pins in a lock will vary but for most front door locks it will be 5 for pad locks it can vary between 4 and 5. In some cases the model number stamped into the base of a lock can give it away.As an example the Master 140 has a 4 pinstacksand that 140 is stamped into the base of the lock.
TOK tension wrenches often called FLAT BARS work from the very top of the keyway just in front of the pins. When you set a TOK tension wrench make sure the prong is not touching the first pin or you may experience some drag while trying to pick that pin.