Waiting 15 to 20 minutes for your nails to dry in the salon is only the beginning of the waiting period.The colour is exquisite. The nail art is sublime. You step out the door of the salon, reach for your keys and – whoops, there goes your perfect manicure. A good salon manicure (the traditional polish kind, not the gel kind) can last as long as a week, but you can wreck it in just a few seconds if you aren’t careful. Professional nail artists have seen it all, and they’ve got some smart tips for keeping nails in tip-top shape.How Long To Sit Tight In The SalonOnce the manicure is done, you’ll be tempted to dash out and get on with your day, but don’t do it. Thea Green, founder of British beauty brand Nails.Inc, said, “Plan to sit for at least 15 to 20 minu