Good descriptions of appearance:

• Tigerstripe; a Bengal she-cat who looks like a tiger. Descriptive? Yes. Within the laws of traditionalism? You betcha!
  
• Rockfang; a tortoiseshell-and-white she-cat with yellow eyes and sharp teeth. Although the pairing of prefix and suffix is a bit odd, it gives her name a double meaning. She was named Rock-kit at birth for her patches of color, and given the suffix -fang upon reaching warriorhood. Not only does it imply that she has very sharp teeth, but it also describes the rocklike patches of color in her fur.
  
• Bluepool; a white she-cat with dark blue eyes. Although cats' eyes are not open at birth, perhaps Bluepool was either named after she had opened her eyes or she was born as Snowkit (or something similar) but given the apprentice name Bluepaw. Either way, the name is a good one because it describes her most striking characteristic: her eyes. She was not the only white-furred cat in FrostClan at the time of her birth, and a name describing her pelt wouldn't stand out.
  

Good descriptions of personality and appearance:

• Thunderstorm; Although Thunderpaw isn't a warrior yet, his warrior name sums him up perfectly--as a violent cat with light brown fur. His pelt color is somewhat similar to lightning, although his mother probably named him in reference to the darker color the sand becomes when wet, especially after a storm.
  
• Iceheart; A black she-cat with bright blue eyes. Her prefix Ice- describes not only her eyes, but her cold-on-the-surface personality. Iceheart was the warrior name of Icestar, who is roleplayed by Lexie.
  
• Thornheart; A jet black tom with jagged white stripes. He's menacing and a bit too ambitious. The Thorn- prefix represents his dark pelt and his personality as well, for obvious reasons. He is roleplayed by Ally.
  

• Anything that has to do with what is sacred to cats or humans. That means Moon-, Sun-, Star-, Soul- (and also -soul), -spirit, Angel-, and the like are out. Cats don't know about angels and demons and other things that are known purely to humans. They wouldn't name a cat after the moon, sun, or stars because it's sacred to them. Also, what will happen to poor Starlight if they're the deputy and the leader dies?
  
• Any one name part more than two syllables and any name more than four syllables. Long names are awkward, face it. I'm sure you'll get just as sick of typing out Chrysanthemumflower as I will.
  
• Any name that is disrespectful to the cat. Death-, Dead-, Burning-, and any other names with strong negative connotations are never a good bet. Warriors are dedicated, honorable cats who fight for their clan and its well-being. No queen would ever give their son or daughter a disrespectful name, whether intentionally or not.

• Wild-; All the feral cats are wild. None are more wild than the others.
  
• Kit-, Paw-, and Star-; Obviously, nobody wants a kit called Kitkit, nor an apprentice called Pawpaw or a leader called Starstar.
  
• Any twoleg object. No Planeflight. No Oreopelt. No Inkspill.
  
• There are more which I'm not thinking about.