By age 46, many men have accumulated a lot of decorative "stuff" that they'll likely never use. Instead of adding to the clutter with yet another picture frame or tie, give your special man a genuinely useful gift or exciting experience that will help make his life easier and his memories more colorful.
Help him stay in shape with the gift of fitness. Hire a personal trainer for him or get him a gym membership. Check beforehand for age-appropriate classes he may enjoy. If he doesn't have time for gym visits, consider a treadmill or elliptical machine; he can stay in shape while watching TV at home. If he's an avid athlete already, help him stay that way with new fitness equipment: weightlifting gloves, a new bicycle, custom-made golf clubs or new running shoes.
Keep him comfortable and entertained while on the go. Consider a stylish monogrammed luggage set or a leather passport wallet. If he takes extended trips, try giving him foreign-language lessons or a mini guidebook library. You could also get him a subscription to a discount travel service. If he's often literally on the road and driving, consider a hand-held GPS; add a lifetime upgrade and he'll be set with up-to-date information for the rest of his traveling days.
Lend a hand in maintaining his professional career. If his wardrobe needs work, send him to a tailor to have a few new suits custom-made. Or, you could outfit him with an attractive new watch or cufflinks. Upgrade his cell phone to a smartphone for easy access to his calendar. You could also get him a mini laptop for taking to meetings.
A mature man may enjoy more sophisticated drinking. Get him a stylish crystal decanter and glasses for his favorite scotch, an engraved flask or a bottle or two of imported wine. If he enjoys an adrenaline rush now and again, get him flying or surfing lessons or a ride-along in a stock car with a pro driver, or take him whitewater rafting or skydiving. If he prefers quiet relaxation, give a day of pampering at a men-only spa, a luxurious bathrobe, imported cigars or a boxed set of his favorite TV show.