When you write out a character profile* there are a few key little things to keep in mind that could encourage a longer, more descriptive list. You don't necessarily need to write them down; just having your mind in this gear should help. What you do is you give a "front seat" in your mind to the fact that your character has A) eyebrows, B) a nose, and C) fingernails. It's a little bit weird, but what this will do is set your brain to thinking about details and the tiny nuances about the character's appearance. Many things you read will leave the description to little more than hair, eyes, physique, clothes, and the presence of freckles when in reality there is so much more to how a person looks. Now, of course, you don't need to keep the focus on these specific three things. I could have easily said eyelids, belly button, and pinky toe, and it would all be the same. The point is to use these small, commonly ignored aspects of a person's appearance to get yourself thinking about him/her in a more well-rounded way, thereby knowing your character much better.
If you read something written in before this modern style of writing in which everything is simple and to the point, you'll notice that the writers like to use physical description to indicate personality and occupation. They were also much longer and more descriptive with the use of several comparisons. There is a very good example of this in The Three Musketeers by Alexander Dumas (one of my personal favorites, by the way--very exciting and funny) in the description of the young protagonist, D'Artagnan:
"When arrived there, the cause of the hubbub was apparent to all.
A young man--we can sketch his portrait at a dash. Imagine to yourself a Don Quixote of eighteen; a Don Quixote without his corselet, without his coat of mail, without his cuisses; a Don Quixote clothed in a woolen doublet, the blue color of which had faded into a nameless shade between lees of wine and a heavenly azure; face long and brown; high cheek bones, a sign of sagacity; the maxillary muscles enormously developed, an infallible sign by which a Gascon may always be detected, even without his cap--and our young man wore a cap set off with a sort of feather; the eye open and intelligent; the nose hooked, but finely chiseled. Too big for a youth, too small for a grown man, an experienced eye might have taken him for a farmer’s son upon a journey had it not been for the long sword which, dangling from a leather baldric, hit against the calves of its owner as he walked, and against the rough side of his steed when he was on horseback."
Then, of course, there is the use of this quite often in Sherlock Holmes novels, but given Holmes' character as the primary reason for this kind of description it hardly counts so I won't add it here. But on personality description (and you can really do this with any part of a description), you can do the same trick mentioned above with aspects of a personality. You can think that this person has a favorite type of weather, a TV show (or other form of entertainment) they used to love or hate as a child, political opinions, a way they jam out to music, and a way they fidget for different occasions (tapping fingers when bored, itching nose when hiding something, etc.) and so on.
I hope this helps. But then again... it's just a theory, a writing theory. Thanks for reading. ;)
*Please note that the character profile, as I'll be talking about it, is different from the character description. A description will be in the actual writing, and a profile is more of an outline to start off and get to know your character. It is not publicized, and it usually looks something like this:
Name:
Age:
Looks:
Personality:
History:
etc....