Do you mean after an accident, or in general??

After an accident, I clean the spot with Woolite pet stain remover, and then spray with Arm and Hammer foam (for pets, of course). If the spot is real bad, I also use Nature's Miracle.
I just bought a Bissel spot remover--a handheld little steam cleaner to extract spots from the carpet--but I haven't had to use it yet.

I also use Arm and Hammer powder that I put down before I vaccuum--works very well.