There are currently several different types of heel available in FFS; the pointed heel (which was invented by the French and is predominantly a European style), the Cuban heel (the most common and most authentic), the Havana heel (similar to the Cuban but thicker and ending higher on the calf) and the Manhattan heel (a more recent design).
There are only a handful of manufacturers still making full fashioned stockings, one of which is Magnolia Hosiery here in the United States, who have been making FFS on the same machines continuously since 1954. You can still order from them directly! What Katie Did offers a nice selection of FFS including contrast colored seams (most recently blue and red). FFS come in a number of solid colors, in full contrast beige with black seams and also black feet and seams.
Another type of stocking which was introduced in the 1950's is the RHT or Reinforced Heel & Toe. These are seamless and give more casual look. They can also be purchased from Magnolia and What Katie Did.
Leg Avenue and a host of other brands offer modern seamed stockings. The difference between these and FFS is that the seam is sewn on afterwards as a decoration and is not part of the stocking construction. Many people find these kinds of stockings more comfortable because of the stretch (they are more akin to a pair of modern pantyhose than FFS are).
Whichever type of stocking you choose, make sure that your seams are straight. You can achieve a straight seam by carefully gathering the length of stocking up so that it is all in your hands, place the toe of the stocking on your foot and then point your foot on the floor. Slowly pull the stocking up your leg, keeping a finger on the seam and guiding it along the center of your leg. You can try spraying the back of your leg with a little hair spray to make the stocking stay put before putting it on as well.
Whether you choose fully fashioned, RHT or modern seams, in order to up your "oomph" quotient, a pair of stockings is a must have!