DIY Mounts for aero style cross bars?

How do you make a mount for an aero style cross bar from thule or yakima for example?
I have seen U bolts used for yakima round bars to mount custom gear (awnings, tubes, etc...). And various L brackets and such bolted onto the Thule square bars for the same use. Like this picture:

But does anyone have a good method for mounting your own stuff to the aero style cross bars on these rack systems? Their shape makes it a bit more complicated.
Maybe I should avoid the aero bars if I plan on DIY routes?
Thanks!

 

I think I figured out a solution. Should be able to use Yakima Mighty Mounts 39H and some bolts to attach most anything I would want on the corebars.