Beauty is in the eye of the beholder. While that is often true, here are some tips on making your area the best it can be.
Spelling and Grammar: Nothing is more annoying than an area with descriptions full of typos and grammar faux pas. Not only does it look unprofessional, it is difficult for players to enjoy or involve themselves in areas with errors.
Creativity: Remember, this is not real life. Aardwolf is a fanatsy world and the monsters that inhabit it should be no less. While peasants, bears, rabbits, dogs, cats, and horses are cute, they are mundane and boring. Brownies, Imps, Curs, Elementals, Drakes, Golems, Fiends, Harpies, Titans, Satirs, Wyverns, Gargoyles, Wisps... the possiblities are endless! Better yet, try creating a race all your own!
Mimicry: Avoid planning your area based on themes, quests and mobs that you like best in Aardwolf. While mimcry is the highest form of flattery, players are more likely to view it as a knockoff rather than a salute. Original ideas are most often the best creation.
Descriptions: Try to be as creative and detailed as possible. You will capture more attention with "a gleaming violet orb, flawless in design and smooth as ice" than "a rock". Rooms, mobs, objects should all be unique as possible and while it takes extra work, it the most important factor between an incredible new land and just another area.
Extra descriptions: People are naturally curious. You can never have too many extra descriptions. Details can only enhance your area. Remember, just like other games, easter eggs really make for a great addition.
Sentinel Mobiles: While sentinel mobs are sometimes neccessary in mprogs, function, and theme; mobiles should, by nature, be mobile. Not only do 30-40 still mobs make for a boring visit, it provides a bot-friendly atmosphere!
Stories and Mobprogs: Mobs should be as interactive as possible whether in story form or mobprog interaction. Even if you're trying to promote a quiet atmosphere or an unintelligent creature, without a story, mob will say 'I don't feel like talking just now.' which is hardly the impression you may want to give.