1. Only buy watches you want to wear. That way you'll never feel like you're stuck with an 'investment piece.'
2. Buy from a reputable retailer. This will ensure you'll enjoy decent after-service care. Also, it's the only guarantee that you're not buying a fake. Some rip-offs are so convincing that only a watchmaker can spot the difference.
3. Be nice. If you form a rapport with a retailer, the store will look after you over the years, even helping you to upgrade or trade-in watches while reducing the sting of depreciation.
4. If you're relatively unadventurous, look to the established brands. Patek Philippe, Jaeger-LeCoultre, Audemars Piguet and Vacheron Constantin among others. They haven't survived for one or more centuries through luck. They also enjoy better resale value if you need to part with them.
5. Be conservative. Nothing dates more quickly than a radically styled watch.
6. Don't buy quartz watches except for knock-around purposes. Regardless of the price -- from GBP 2 to GBP 2 million -- the movements are disposable and, after a while, irreparable.
7. If funds are limited, choose a watch with a strap over one with a bracelet. Bracelets add considerably to the cost. A good watch on a strap is better than a so-so watch on a bracelet at the same price.
8. When buying new, keep all the paperwork and boxes.
9. When buying a vintage watch, ensure that there is a guarantee of at least six months if the watch is being sold as serviced. The phrase 'as seen' should act as a red flag warning not to buy unless you have a watchmaker at your elbow to advise you.
10. When buying at auction, attend the viewing beforehand to see and handle the target of your bidding. Some auction houses will provide a condition report a few weeks ahead of the auction.