Location
The motto for Groundspeak is "The Language of Location".This, more than anything, should be your first clue in
determining if your cache is a stinker. Ask yourself, "Why am I bringing people to this spot?" If the only answer you can come up with is yet another mindless smiley or to annoy as many people as possible then perhaps it's time to rethink ground zero. A woods hide is good. Making folks steamroll an area looking for a micro or forbid one of those nanos four miles out in the Everglades is bad.
Container Selection
The purpose of a cache is to protect its contents. Whether those contents are a slip of paper covered with the initials of a bunch of geo-nerds, or the contents are high dollar, really kewl swag, is really immaterial. If the container won't protect what's inside, it is lame. Quality forrest containers include ammo cans, Lock & Locks and decon kits. Waterproof match containers and bison tubes disguised to look like their surroundings create an environment where destruction of the area is inevitable.. Inadequate containers include Gladware, black & gray film canisters, hide-a-keys, Altoid tins and duct tape covered baggies. These may work great indoors, but they simply will not repel moisture once subjected to the whims of Mother Nature.
Hide Style
If a hide style gets copied too often, it automatically becomes lame. Ammo cans seem to be the ultimate exception. Any hide style that encourages vandalism or otherwise violate Groundspeak's guidelines, (graffiti coords/affixing electrical boxes to structures/buried caches/etc), are bad for the game, and should be avoided like the plague.
Write Up
Your cache page write up is the medium used to present your cache to the community. You should be proud of your cache, and let your cache page reflect that fact. If there are more words tattooed on Rosie O'Donnell's backside than in your write up, folks might get the impression that you don't care about your hide. A bit of history about your site, or some humorous anecdotes about yourself, seem to go over well with the caching community. On a similar note, spellcheck is your friend.
Hints
Your hint should actually help your fellow cacher find your cache. You can be blunt or creative, so long as the message is relevant. A sure fire way to create angst amongst your fellow cachers is to get them to struggle through 10 minutes of ROT-13, just to discern a hint like, "This one is too easy for a hint".
Results
If you see a high percentage of single sentence find logs on your cache page, that is a fairly reasonable indicator that your cache may be suffering from a lack of ingenuity. This trend becomes more pronounced if you see a lot of "TNLNSL" entries. At that point, your cache has reached a lameness critical mass, and should probably be put out of its misery.
Patience
Patience is a virtue, especially in geocaching. If you become immediately hooked on this game, you may find yourself wanting to run right out and hide a cache, as a means of giving back to the community. My advice? Allow yourself the time to gather sufficient experience before creating your first hide. By far the greatest number of lame hides come from folks with more enthusiasm than experience. Hiding a cache is an art form, and even Da'Vinci needed lessons.
Good luck!