I take (2) tarp straps, either new or found on the roadside, cut to length, and glue to the bottom side, let dry and install tank. Glue as so the straps will cradle the tube.
I have a bunch of factory junk tanks with the mounting bolts cracked at the factory welds, and a few with cracks where I rewelded them then tried to solid and pad mount them, the mount that I pictured does not let ANY metal touch the frame of the bike,this eliminates most of the harmfull vibrations, I understand that there are people that do not have access to welders & that there are frames made of alloys that when welded crack, the Idea I posted is just one of my ideas, It worked for me and is still working, I ride alot.