Recognizing the Turns - 2-Foot
Some turns involve both feet, and are called two-foot turns. The best known 2-foot turns are Mohawks and Choctaws.
Mohawk
A Mohawk changes feet, changes direction (i.e. front-to-back or back-to-front), and maintains the same edge (i.e. if you started on a Right Back Outside edge, you end up on a Left Forward Outside edge). The common "step-forward" is technically called a Mohawk.
For most skaters, the most common Mohawks are the RFI-LBI (you sometimes see this before flip jumps, and you often see it when a skater just needs to change direction quickly), and the RBO-LFO (you often see this before waltz jumps, Axels, Salchows).
Choctaw
A Choctaw changes feet, changes direction, AND changes edge (i.e. if you started on a Right Forward Outside edge, you end up on a Left Backward Inside edge). In the Preliminary MIF test "Alternating 3-Turns" element the step from one lobe to the next is a Choctaw (for instance, one of the lobes ends with a RBO edge, from which you step onto an LFI edge for the start of the next lobe - this is called an RBO-LFI Choctaw)
The Choctaw is most frequently performed in footwork sequences. Its a good element to use because its pretty dramatic, and unusual enough that it'll usually get noticed and remembered -- especially if you show that you can do it both ways, and cleanly (quietly with good flow).
In the video clip shown here (double click the image at right), Paul performs both LBO-RFI Choctaws (near the beginning), and RBO-LFI Choctaws (about halfway through).