Kiting is a basic tactic used to kill monsters while avoiding engaging in melee.
To kite a monster, you must be faster than it and have some form of ranged or reaching attack. Back away from the monster whenever it gets close to you; when you are far enough away, hit it with a ranged or reaching attack. Repeat until the monster is dead.
You should keep at least two squares of empty space between you and the monster in case the monster has time to advance and strike you in a single turn. You can even kite monsters that have ranged attacks, provided the range of your attack is longer.
You should avoid kiting in the direction of an unexplored area, if at all possible. Kiting combines well with pillar dancing, especially when using a pillar (or wall) a few tiles across. Kiting can also be used to maneuver a monster into an advantageous position for a multizap.
Kiting has some use against monsters that are the same speed as you, if you can survive a few blows but not an extended fight. If you poison the monster, have Sticky Flame, or regenerate faster than it, you can turn the battle into a war of attrition. Hit or poison it, then back up/pillar dance until it shakes off the poison or you have recovered enough HP, then hit it again. (Like regular kiting, this is ideally done with ranged weapons.) When dancing around a pillar with an irregular shape, the monster may even lose track of you, allowing you to reengage it with more ranged attacks.