Instead of tape, we use ball bungees to tie off the loose ends of the straps. They serve two purposes: (1) impress the customer with attention to detail, (2) when used as shown, the strap is secured over the top of the ratchet strap handle, which helps keep the handle from popping loose (though, without ball bungees, we have never had a handle pop loose).
We buy the ball bungees at Home Depot. You can find them in the section where tarp straps and ratchet straps are displayed. Unlike tape, they are reusable. I have not compared prices but I think you can get ten ball bungees for the cost of one or two rolls of duct tape.
At delivery, they are quick and easy to remove, and there is no waste to dispose of as there would be with tape. Ball bungees will work outdoors too, though their life will be shortened by exposure to road spray and such.
I will not disagree with those who call our ball bungee use overkill. But our customers love it, which is why we do it. The pictured load is a piece of expensive medical equipment being moved from one hopital to another. The shipper watched as we secured the load and was favorably impressed.
We generally use the ball bungees only if the customer is watching. In our "indoor" use, they have to do more with marketing than freight securement. But in outdoor use, as with a flatbed, they have the very practical application of keeping the strap ends from flying about in the wind.