On my ride I use a pair of "Soft Ties" at the bottom triple trees, NOT the bars in the front.
Another pair of "Soft Ties" at the lower shock mounts at the Rear. Sometimes another set in the rear at the top shock mounts.
What kind of trailer you own (rent). Leaf or torsion bar suspension?
My tie positions may not work for you? My Dyna has plenty of room.
If you trailer your bike someone told me the security system has to be programmed for "trailer mode." Otherwise the security light will flash off and on the entire trip and kill your battery. Has anyone else heard or done this?