on where, how deep, wide, etc.
But...if you can close the edges, either with butterfly bandage, tape, stiches or even superglue..then let it heal with some antiseptic, you are reducing the amount of new tissue which has to form.
For scars, I have heard everything from rubbing vitamin e oil (break open the capsules, to..just rubbing the site after it heals for a long time ( as in days, weeks, not just hours.) After the accident and the surgeries, this seemed to work for me. Thin lines rather than raised scars. My leg scars are like rippled paper and don't show up much...but I'm very light-skinned and the scars are slightly lighter.
It also worked on the bird dog who split his chest muscles open and had to have them cure from the inside out. The end result was a lump of scar tissue about 1 1/2 inches long. I keep on massaging it, and it is smooth, or nearly so, now.
Heal fast, suffer little.