If you've got some cash, invest in a Baxley or Condor wheel chock. They're great because they capture the bike once it's rolled into the chock, giving you time to fasten it down. If you don't have a lot of cash, you can get a basic wheel chock that will hold the bike from some place like Dennis Kirk. It's just a curved piece of steel that mounts on to the trailer and prevents the bike from rolling forward or tipping over once it's secured in the chock. If you've got NO money, you can always make a chock out of 2 x 4 scraps of lumber screwed or nailed together. I did this when I first started trailering because I'm cheap and I wasn't sure if I wanted a chock or something like the Strapless Motorcycle Stand (
http://www.ststands.com/main.cfm). I ended up going with the Condor chock.
My method is: Push the bike up into the Condor wheel chock. The fasten two straps, one to the bottom of each fork slider, and fasten them to tie points at the front corners of the trailer. Next, attach a tie-down to the left rear corner of the trailer then loop the strap around the top of the rear wheel and attach it to the right rear corner of the trailer. Rachet down the front straps, then the rear strap. Give the bike a good shake. Done. So far this system has worked for hauling a bike to my local track (30 miles by freeway). I'll be testing it further in March when I haul my bike down to Barbers.
I'm not a big fan of the Canyon Dancer rig because I worry about putting all that strain on the clip-ons, and I also worry about bodging up the throttle sleeve.