I generally eyeball a handful of things about a laceration.

1.  Location: Is it in an area we consider "high dollar real-estate?"  (face, hands/wrists/joints, around major vessels/nerves, etc).  These require a more careful assessment, including nerve-function, and moving any digits/joints through their full range-of-motion (with the wound open) to assess for tendon/joint injury.  

2.  superficial or deep:  Superficial tends to hit less important stuff, though there are still cosmetic issues

3.  Contaminated or not?  (this determines how aggressively you irrigate it, or in some cases whether you close it at all).

4.  How old is it?  (older wounds have a higher risk of infection, and are sometimes left open)

5.  Mechanism: Blunt or sharp trauma (the former creates more tissue damage, and a worse cosmetic result).  Any potential for foreign bodies that will need removal?  

Truth.