The Panorama Trail to Glacier Point in Yosemite National Park is one of the most highly-trafficked trails in the park, but for good reason. After driving up Glacier Point Rd (closed in the winter), you arrive at the top of Yosemite in the high sierras with stunning views of Half Dome, Vernal Falls, Yosemite Falls, and the valley below. The trail is much longer than the 0.5 miles out-and-back here, but you start at the end of the parking lot and work your way north to Glacier Point - follow the trail and the traffic.
Once at Glacier Point, you can follow the small trails that lead closer to the edge of the cliff, but do this at your own risk as there is little-to-no warning that you're about to get to the cliff's edge; however, the freedom of the small trails around the point are nice to get away from the crowds and to soak up the views of this amazing lookout point.
Not much else to say other than it's a long drive to Glacier Point, but you can hike up along the Four Mile Trail to Glacier Point for a 9.6 mile trip instead. However, this is the easier way up.