Q. When should you book a last-minute flight?

A. On Wednesday from midnight to 2 a.m. Airfares are updated about 250,000 times a day, says Peter Greenberg, travel editor for NBC’s Today show and author of The Travel Detective (Villard, $16, www.amazon.com). So how do you get the best last-minute deal? Most airlines start their sales on Friday afternoon and compete with one another all weekend. The competition stops on Monday — “but that’s not when you call,” says Greenberg. “You call at one minute after midnight on Tuesday, meaning Wednesday morning.” Why wait? “Because these days, when you book a fare on the phone, you have 24 hours in which to purchase the ticket. So by midnight Tuesday night, all those discount fares booked by people who didn’t purchase them come flooding back into the system, and for a brief period of time — between an hour and two hours — you can get those deals.” One more thing to remember: Make sure you’re calling the minute after midnight on Tuesday in the time zone of the airline’s base location, which you can find on its website, usually under “contact information.”

Q. When should you have your picture taken?

A. Late morning or early afternoon. Models have makeup crews to make them look fresh even first thing in the morning, but the rest of us should give ourselves a few hours to shake off the puffiness and sluggishness of sleep. “Middle of the day is best,” says Joseph Pluchino, a portrait photographer in New York City who teaches at the School of Visual Arts. “You don’t look like you just woke up, but it’s not so late that you’re looking tired.” Michael DeVellis, director of the Powder Group (www.thepowdergroup.com), a network of makeup artists, recommends getting that photo snapped soon after your makeup is first applied, not later in the day, when you’ve been through your second or third touch-up. “The fresher look will come across on camera,” he says.

Q. When should you water your garden?

A. Early morning. “Generally speaking, between dawn and the heat of the day is the best time to water,” says Panayoti Kelaidis, director of outreach for the Denver Botanic Gardens. “If you water at night, it can encourage certain diseases or bacteria, because the plants are saturated when the water can’t evaporate.” Chip Tynan, horticultural-information specialist at the Missouri Botanical Garden, agrees: “The very early morning hours are the best time,” he says. But Tynan admits he sometimes leaves the house before he gets the chance to irrigate his plants. “If you’re running your sprinkler during the heat of the day, then a lot of that water is evaporating before it gets a chance to soak into the ground,” he says. “The plant should have ample time to dry off before nightfall.”

Q. When should you cut a flower from your garden?

A. Right before it blooms. “On a rosebush, for example, before the flowers come, you get tight little buds — and if you cut them too early, they won’t flower at all,” says Matt Pettle of the Chelsea Garden Center, in New York City. “But just as the flower emerges, cut it and put it into water.” Tynan agrees: “If you go ahead and cut it when it’s still in bud stage but the buds are showing color, then you’ll get to enjoy the flower when it first opens and usually for many days afterward.”

Q. When should you buy shoes?

A. Late afternoon. “Your feet are at their biggest size at the end of the day,” says podiatrist Jane Pontious, associate professor of surgery at the Temple University School of Podiatric Medicine, in Philadelphia. “And you want buy shoes at the time your feet are at their largest size.” After all, those perfect black pumps may fit just fine in the morning, but it’s after a full day of being on your feet that you’ll need them to be the most comfortable.

Q. When should you go on safari?

A. The dry season. The peak safari time is in the dry winter months, as this is when the game concentrates around the water sources, according to the South Africa Tourism Board. (Winter in the Southern Hemisphere begins in June.) The theory is, the more numerous the animals and the more conveniently crowded together they are, the better the pictures you’ll get. Winter is when the great wildebeest migration starts in Kenya and Tanzania, during which you can see millions of these animals, along with zebras and predators, galloping through the Masai Mara National Reserve and the Serengeti.