I have been experimenting using a little engraver tool I use for jewellery making.
If I glue brackets onto all the teeth of the model, them thermoform 1mm plastic over the top I can use the little rotary engraver to cut away the plastic around and over the brackets. This leaves them exposed as they would be during treatment. I can then put on wires and ligs (blue today!) and they are just like real braces - the bracket bases are held by the plastic but the rest of the brackets and wires are like real braces.
I can even use the elastic hooks for elastics - I put brackets with hooks on most of the teeth so I can try different elastic configurations. Very cheap to do, I think my vacuum former was £100, and after that the supplies are really cheap - £5 for a set of brackets, stick of ligs, and an archwire for example. All from Ebay.
The appliance it makes is like a nice mix of removable and fixed braces, I make it to cover my whole palate like a hawley. I am going to see if I can find a cheap Herbst to put on, I used to see used ones on German Ebay but not now, maybe they are against the rules.