Dan,

 

I'm using "L" brackets made from 6 bid.  I just wrap 6 bid around a 2x4 and cut it into 1 1/2 by 1 1/2 brackets, drill and attach a nutplate.  For brackets that require a little extra strength, I'll do a 2 bid layup over the attached surface.

 

I don't know how to work with aluminum!  :-)

 

Mike