1. Most of the time, fakers fake the same brands. 95% of fakes are Rolex, Breitling, Cartier, Patek, Piaget, Vacheron. If you find a nice old Tissot chronograph, you have a much better chance of it being the real thing. Then again, I got fooled by a superbly faked Corum Admiral's Cup once-- because I never heard of anybody faking a Corum. 2. Quartz movements sweep the second hand with a jerk, automatic movements sweep it smoothly. Since Rolex, Patek, and (most) Cartier do not make quartz watches, the jerky second hand is a good quick test. But remember, there are fake automatic movements, too. 3. Fakes with stainless bands almost never use solid band links. You'll see folded edges, plus screw pins with slots. Real Rolexes and Breitlings have solid band links. Then again, there is so much Rolex fakery that there are now even fake solid Rolex bands. 4. Fakes often lack serial numbers, or the serial numbers are all the same. If it does not look individually rollmarked, beware. 5. Fakes use crummy leather band clasps with a tubular hoop, and often do not repeat the maker's mark on the clasp. Then again, I've seen Cartier fakes with Cartier clasps. 6. Almost nobody fakes half a watch. If it's fake it's all fake. There are no ready supplies of real Rolex cases or movements waiting to be combined with a fake case or movement. 7. If the movement is not marked, chances are it's a fake. Real makers almiost always add an engraved bridge or rotor. And if there is no rotor, it's almost certainly a fake, since manual wind mechanical movements are nearly extinct. 8. Look at the crown. On a Rolex or recent Breitling, it should be marked. It should show no wear through the plating, and no discontinuity of color with the case. 9. Your best friend in examining a watch is an 8 power loupe. You'll see plating peeling at the edges, the crudeness of a poorly silkscreened dial, a plastic crown jewel, a mismatched crown. Use a loupe on a couple of good watches to get a sense for what you're seeing. 10. Don't buy online and especially not on Ebay. Repeat, don't buy on Ebay. It truly is "E-prey" when it comes to watches. There are a hundred reasons even a legitimate watch might be a poor value, and a thousand ways it might be fake. As Obi-wan Kenobi said, it's a "hive of scum and villainy."