Whenever possible, take the scenic route
If you’ve got the time, take the scenic route. Better yet, plan to have the time to take the scenic route. When planning your trip, we’d advise avoiding all major highways: the 5s, 80s, 90s, 94s, 15s, 70s of the country. Sure, you can get there faster on the main route, but if you’re only interested in getting somewhere quickly, take a plane.
Even if you must stick to the main highway, look for opportunities to branch off and explore the surrounding area. One example: say you’re driving from Las Vegas to Salt Lake City on 15. Towards the end of the drive, you’ll start wearing out. You’re always driving by gorgeous mountain ranges, never through them. To correct this injustice, at Nephi, UT, exit Interstate 15 and take Salt Creek Canyon Road through a section of the Wasatch Mountains, rejoining 15 in Payson, UT (if you must).
If the twists and turns of Salt Creek Canyon Road don’t fully envirgorate you, there are plenty of opportunities to jump out of the car for a short hike, a long hike, or a long view over the Wasatch Range. At the peak of the road, you can even look down on Utah Lake and out across the desert, far below.