I really like the wheel chock from Princess Auto (Canada), i believe Harbour Freight in the USA has a very similar model. Usually can be found on sale for $40-50. Makes securing a bike solo very easy. I prefer to use 2" wide straps with a sewn loop on one end, no hooks to touch the bike. I loop through the lower triple trees and then secure to the trailer mounting point. I have those pulling forward into the wheel chock then on strap through the rear wheel pulling backwards. In this pic the rear strap is off already but you get the idea. Second pic i had a strap throught he front wheel to hold it in place as i secured it. Hard to tell from pic but the trailer is on a fair incline.
1990 Jayco 250 Special
2008 Ram 5500 DRW 6.7, Cummins, Aisin auto
Holland/Binkley 5th wheel, Reese Dual Cam, and more
232,500 kms in 2013
200,000 kms in 2014
160,000 kms in 2015