“Make a deal with your mind,” says Sam Horn, author of ConZentrate. After it does what you want, you’ll do what it wants. An example: “I’ll balance my checkbook for 20 minutes, then reward myself with a break!”

Brain train

Bodybuilders bulk up by squeezing out more reps after their muscles are quivering with fatigue. When you’re tempted to stop working, say, “just five more minutes.” But don’t bully your noggin when you’re truly wiped out. Instead, hit the sack and get up early to finish the job.

Establish rituals

Docs scrub in, musicians warm up. Your mind needs cues, too: Don a “cleaning outfit” every time you whip out the Scrubbing Bubbles, or pop in earplugs to do your quarterly report. It’ll tell your cerebellum, “We’re on!”

Flip the script

It’s hardest to hunker down for tasks you hate, so why not alter your perception of them? “Even doing taxes can be seen in a positive light,” says Horn. Instead of griping, think, “I’m so privileged to live in this country and I’m proud to support it.”

Feed your head

“People concentrate much better when they have good blood sugar levels,” says Daniel Amen, M.D., author of Healing ADD. Consuming small meals high in protein with healthy carbs prevents lassitude. If you lose focus midafternoon, skip bread, pasta and rices at lunch.

Go fishing

Folks with low levels of omega-3 fatty acids are more prone to depression, dementia and ADD, notes Dr. Amen. If you don’t eat wild salmon or other deepwater fish at least twice a week, take an omega-3 supplement (and make sure it contains EPA and DHA).

Say “ohhhm”

Meditation “stimulates the brain’s frontal lobes,” which helps concentration, says Dr. Amen. Sit with your eyes closed for at least five minutes a day and focus on your breathing.

Teatime

Dr. Amen recommends trading in your daily java for a cup of green tea — it contains theanine, a mild stimulant that also aids concentration.

Clean living

Aim for eight hours of sleep each night and lots of aerobic exercise (heart health = brain health). Also, avoid toxins, from air pollution and sleeping pills to alcohol, urges Dr. Amen.