Depends on
- how you want it to look like
- how well the ends of the trace are accessible
I like a clean job but don't try to make it invisible unless that's easy to do. Short lengths of low-current traces - especially fine SMD ones - can be fixed with single strands of braid (or a pair twisted together).
For higher current or longer lengths I use a fine cable, lacquered or telephone wire running from one solder point to another, completely bypassing the damaged trace - much more durable that way.
Some small dabs of hot glue (easier to remove that superglue) provide stability if required - not necessarily pretty but reliable. You won't want anything to fall apart the next time you're fixing something else.
