I've towed plenty of bikes and the best thing was the invention of seat belts.
Once seat belts came along, there was an almost endless supply of cheap flat webbing material, that was also quite thin.
Using rope will give the towee a very sore hand and the tower will be forever stopping and waiting for the towee's hand to get feeling back.
Yeah, through the forks, up to the bars, then out to the L/H grip, once around the grip and hold with the hand.
One of the more difficult tows I've done, was about 100 Km's down a sandy track, towing a german tourist who had ripped the alternator off her kawasaki.
She was really very good, we went around 20 Km/h maximum for the whole time with a break for dinner under a tree. Saw her in Germany about 5 years later and she couldn't thank me enough.
Once towed a Mini Minor with an old late fifties R50 in the late sixties. When we stopped he had to get out and push the car to get things rolling and then we tootled along at a sedate 15 Mph or thereabouts in second gear.
One of the permanent things in my tank bag is a 25mm wide x 4 metres long piece of webbed material. It serves two main functions. It's main function is to allow one to tourniquet a tyre so that you can get it inflated on the side of the road. The secondary function is as a tow rope. It also goes well as a clothesline, tarpaulin holder, and, a strapper on, of anything that needs strapping.
Mick.