Don't "over-do" the cinching though. If you put too much pull on the front shocks (I mean a lot of draw down as you could with ratched straps), it could cause the fork seals to to start leaking & from then on, they will not stop. That is from experience, not with the Rocket though. I had to replace 2 sets in the old Yamaha until a friend shared his knowledge with me on this.
Here is another tip. If the straps you use have hooks on the ends (most of them do) and you will be hooking through a "hook eye" on the trailer, take precautionary measures as follows.
When the suspension compresses due to a bump or dip in the road, the straps will sag due to the loss of tension (duhhhhhhhhhhh). Experience is speaking once again. When this happens (the sagging straps), the lower hooks can release from the eyes and you suddenly have a catastrophy. I always "double up" on the front straps. I'm able to do this because the trailer I built has 6 load securing eyes, 4 for the front & 2 for the rear.
Anyway, to the point. Get yourself some good heavy rubberbands, make a couple of twists in them (you know what I'm describing, just like around the newspaper), slide the loops onto the lower hooks (continue to hold the rubberband with one hand, the hook in the other), put the hook through the tie-down eye and place the loops onto the end of the hook again. This assures that, even though the straps see slack from a bump, the hooks are secured to the eyes and will not "drop out".
I always set my straps up first on the trailer (affixing the lower ends to the eyes with the rubberbands as described) then throw the excess strap length over the sides of the trailer (if your trailer has sides). Then as I roll the bike onto the trailer & nose the front tire against the center front post, I can let go of the grips while straddling the bike, grap one of the two straps on each side & hook the upper ends to the handlebars temporarily & draw out the slack. This will hold the bike while you "unsaddle" & grab the other two front straps & find a stout hold on the front frame. Then adjust the handlebar straps accordingly. The rear is not so critical but you don't want the back tire hopping around & changing your "departure" angle for getting the bike "straight" off the trailer. I usually cinch down the rear, the grap another strap (& maybe a piece of rope with a loop tied in one end) and pass a complete loop around the rear tire (at the very back) and secure the ends of that attachment "forward" to help keep the bike pressed against the front center post. Because I designed the trailer, the center post is there so that I can "lash" the front tire to it with a rubber bungie cord. This also assists in keeping the front fork from turning while bouncing down the road.
Call me silly but I've never "lost" a bike. Now, with the experience of the straps coming off the eyes of the trailer and not "over cinching" the front suspension, I feel pretty confident with hauling a bike. One trip was over 1000 miles round trip with not problem. Heck, when I picked up my Rocket, I had to trailer her over 2 1/2 hours home but the "lashing" experience I have made me pretty confident she was staying put.
One other mention, the upper hooks don't "jump" off the frame or the handlebars when the straps go slack so rubberbands are not really necessary there. Also, somewhere along the way I acquired two short nylon straps (about 12" long) with loops sewn into each end. I'm able to loop those straps around the frame at the rear & pass the upper strap hook through the loops, in lieu of searching for a place to put the tie-down hook directly on the frame somewhere.
Experience will help with your comfort in trailering a bike. Stop after a few blocks & check everything, stop after a mile & check, stop after another few miles & check until you convience yourself that baby is going to stay with you. I'm telling you, my vehicle, trailer & bike could "roll" & that bike is staying put in the trailer, guaranteed.
See ya.