I've been sharpening my own chains since I wuss about 12 years old, I hate to run a dull saw or have to push it through the wood, I have never used anything but a round file for the teeth and a raker file for the rakers, 2 short strokes on the rakers with a new chain and again about 1/2 way through the chains life.
Two common mistakes I see people do is first they don't use a straight stoke with the file and the second is they don't cut deep into the bottom of the tooth, the file should almost be hitting the links of the chain on the bottom, this gives you a nice knife edge on the top of the tooth. Of course as we get older three more tools are very handy, cheater glasses, good light and a good vise!