Love it. Do it regularly.
Ride at my own pace, stop when I want, no schedule or trail to follow but my own.
Some days I ride and ride and ride and ride and only stop to catch my breath at trail intersections... other days I ride a little, stop and set up the camera to shoot for a while, pack up and mosey down the trail, do the same thing again... eventually I'll make my way back to the road and head home.
Sometimes I'll load up a few mags and ride somewhere I can send some lead downrange.
But yes ... there are risks associated with solo /out/ing.
ALWAYS let someone know where you're going (roughly) and when you'll be back.
Plan on spending another night /out/ there. For day trips bring shelter, a night's worth of food, a flashlight, firestarting/signaling gear...
Obviously first aid equipment, and know how to use it. What's in your kit should be somewhat terrain-, wildlife-, and season-specific.
Communications... some way to get a message out. Preferably more than one.
Cellphones are fine when they've got battery power and signal. Mine freaks out when it goes out of service, ramping up power and draining the battery real fast. Put it in airplane mode at the trailhead.
I carry a two-way VHF/UHF radio, programmed with many local repeaters/emcomm towers.
SPOT is okay, though I have my dislikes about it. A PLB is a better option.
If something goes wrong, have the capability to "check in" and relay some information out.
Navigation ... know where you are? Got a map of the area, and know how to locate yourself? GPS's are great when they work, but again, bring backups (ideally something non-electronic).
My solo rides are always a little more tame than when I'm with one or two others.
