I LOVE riding alone. Just think, you don’t have to worry about somebody else’s skill level, when they want to trot or canter. No slowing down or speeding up to match the other horse. You can listen to nature, sing to your horse, talk to him/her about your problems or ideas! It’s also fun to ride with others, but you are really missing out if you never try it alone.
People think I’m crazy, because like GTD, I rarely think twice about going out alone. The second or third ride I did on my OTTB was alone on a trail. Sure, he acted up. I soothed him. At one point I was prepared to jump off when he started rearing and bucking a bit, but I hung in there and he settled down. His big problem was confusion. He’d never been out alone, ever. He also wasn’t used to going bitless. We were going to have to face going out alone at some point, and I elected to do it sooner than later.
I came back exhilerated, only to get a talking to about being irresponsible and a verifiable nut case. While I have no argument about the nut-case thing, I wasn’t being irresponsible. I was training my horse. The options were to try to find an experienced riding partner with a calm horse or to go alone. I wasn’t about to invite an inexperienced trail rider or horse to go along when I knew my boy would likely have at least one hissy fit! Now I have to get him used to going out in groups. :lol:
If you or your horse get nervous on the trail, sing. I can’t remember anything but Christmas carols and the Star Spangled Banner, but my horses don’t seem to care. Singing will keep you breathing, and your horse will at least partly focus on you and not on potential spooks on the trail. 
If you haul to a trail, practice loading and unloading by yourself before you go. I load my horses while standing next to the ramp so I can close the butt bar as soon as they are on. If your horse is used to you leading him/her on, they have a chance to back out before you close the butt bar. Some horses stand there quietly enough for this to work, but I worry about what they’ll do in the few seconds it takes me to walk back and put up the bar.