And remember, if all else fails, a eyebrow shaper or trimmer is indispensable for ripping out those tiny stitches. They can be purchased at about any drugstore, two in a package for next to nothing -- I'm talking 2 or 3 dollars! They can be found on the cosmetic aisle and I believe Sally Hanson makes them or I have one with "Trim" as the brand name. It's such a great tool I should buy stock in the company!! To use it, first use your seam ripper to remove the first few stitches to get it started and then just pull the seam apart and gently rub the blade over the stitches.
PS -- it also helps to have a third hand so I put the piece under the pressure foot. The foot holds the fabric steady while I use my lt hand to pull the seam open and my rt hand uses the cutter. Hope this makes sense........I've become a champion ripper!!