This is one of the few classical hitches that is truly useful and reliable.  Its security is admirable and it always casts off without trouble after use.  Just remember that a true Timber Hitch must have at least three tucks contacting against the object.

Beware of using this hitch around a very large object that might keep the tucks from being clamped down securely.

The one bad thing about this hitch is that it is so simple, that some don't take the time to really study and memorize it, and will sometimes wrap the rope around the wrong leg, which will not result in anything but junk.  Remember to wrap the rope back around the leg from where it just came (left side as shown above).  If you did, it should form an eye for the standing part to run through.