If you have a teacher, mentor, or even magic shop owner that can do it well, he can show you the key points in the space of an hour, and you'll get the knack very quickly. The feel of cutting exactly 26 cards is really easier than it sounds and you can tell if you're off as you're getting ready for the actuall faro. The key points of perfect alignment of the packets, starting at the corners and holding the packets TIGHT and at the correct angle were the major points that I learned that made it much easier at the beginning. I'm a big proponent of a teacher or mentor, which can save a ton of wasted time learning a move improperly. Without a good teacher, I would have wasted many hours and probably ruined a good many decks trying to learn it by myself. Once you get the feel, it's almost automatic.
Many tricks don't require a perfect faro all the way through, and it's very easy to get the top stock perfect for many tricks, including stacking, and that that is enough in many cases. I still have to look carefully for a perfect faro, but my teacher can do it without ever looking at the deck, although he prefers to catch at least a quick glimpse to prevent any embarassing side effects if you miss a few cards.
Once you have the knack you'll wonder what all the fuss is about. But, under fire if a trick requires multiple perfect faros, then I'll usually steer clear to avoid embarassment if one or two cards end up together when I'm more nervous than in practice sessions.
Question: I always forget the difference between an in-faro and an out-faro. I assume an out faro means the top and bottom cards in the same positions, which means most of my faros are in-faro's if this is the case. Is this correct?