You're not really a perfectionist, you just can't stand that torn, burned, ripped or stained section of pile carpet right in the middle of your living room. Even if you've performed routine carpet care and maintenance you can still end up with a damaged piece. What you need to do now is cut out the offending section and put in a scrap. It's not the most difficult of home improvement or repair projects. But you want to get it right or you'll just end up cutting out a larger piece and trying it again.
The first step in this kind of carpet repair is to secure a suitable replacement scrap or square. Usually you'll find a match from remnants from the original installation. In some cases, you may have inherited the carpet from a previous owner and can't locate a stock in the attic, basement or garage. Realtor.com suggests you remove a patch from a carpeted area that never sees the light of day, a section from the back of a closet for example.
For a tiny mark or burn, you can have a carpet contractor come in with a tuft setter. You tear out damaged tufts, harvest good tufts from an out-of-way section of carpet and put them in with the setter - just like performing a hair replacement project on a bald head.
Steps in small-scale carpet repair
Find a remnant large enough to cover the damage completely with room to spare. Lay it down over the damaged section as a template and, with a utility knife or carpet shop "cookie cutter" trace the remnant all the way through the damaged section of carpet below. Use a T-square or ruler to set straight lines as you cut. You should end up with a near-perfect fit.
Position the remnant into the new hole, lining up the direction of the pile to match the existing carpet. This will ensure that the color looks uniform all across the carpet with the new piece in place. You can buy a solvent-free carpet seam adhesive in a home improvement or carpet store. Put a bead around the patch and let it dry. It will keep the edges from unraveling.
Last, apply a perimeter of double-sided carpet tape on the floor where the replacement section will go. Put in the remnant and press down. Hint: if you have a weighted object large enough to cover the patch, lay it down for a half hour to ensure a solid bond.
Brush out the pile and you're done.
If all else fails and you need to lay new carpet, call in an expert for an estimate.