As promised with text for ya Cruz...
Here's Cruz's 390 with a US-10 about 3/4 full mounted onto the tank adapter.
The tank adapter is mounted in reverse with the plastic quick release clips now at the rear of the bike. The strap goes behind the indicators and straight underneath the guard to the other indicator and then the tank adapter. Most important thing is to have the tank adapter mounted tight. If you have no indicators mounted then you can easily mount a steel D clip in the same place either side to feed the strap through and back to the tank adapter.
You may notice that the quick release clips are broken and have been replaced with a straight strap instead. The clips broke during a high speed incident with a closed gate and a fence, but that is the only damage that occurred which is a big thumbs up for the bags strength and resistance. The front blue connector straps are generic straps from a camping store that I always carry as spare tie downs anyway.
If I am taking a fair bit of gear I use the bags as a US-20 connected to the tank adapter and a US-10 attached either side of the 20 as this seems to distribute the weight better and the side bags are partially supported by the plastic side guards of the tail section which also keep the exhaust away from the bags. Have used this setup for approximately 3000 klms mostly hard off road riding with no problems.