As a teacher I usually have a bit more time off than friends and family so I end up going out alone as well...A few general points and then some specific ones:
1) Keep your vehicle in good working order. Sounds obvious but when you wheel alone your truck MUST work.
2) File a flight plan with your family before going out, and with people who might be able to unstuck you should you get stuck. If no one knows where you went then ....
3) Get a HAM mobil unit and know if there are any repeaters where you're headed
4) Consider a satellite phone, I don't have one but I wheel with several people who do. I'll likely get a sat phone when I begin taking my little boy our wheelin.
5) Get as long of a winch line as you can. I have a 100' foot line, an ARB winch extension strap, and I carry my old winch line as well , in total I have around 300 feet of line which just gives you access to more anchor points.
6) Carry a shovel
7) Carry a sleeping bag, food, and extra water at all times. If you get stuck you might have to spend the night there
Lastly...
If you travel alone, you just have to accept that something might go wrong. You'll never be able to fully eliminate the chances of something happening , all you can do is stack the deck in your favor as much as possible...
Wheeling alone has a lot of perks I must say , you set the pace, choose the route, and no one kicking up dust in front of you!
Here's a trip report I made of wheelin the Rubicon in a day by myself:
http://www.expeditionportal.com/forum/threads/150365-Halloween-on-The-Rubicon