I will occasionally fabricate sheetmetal to join anything with the circuit on it to either the pot holes, or jack/footswitch holes.
I prefer methods that don't require drilling the box or using some sort of adhesive that could make disassembly down the road more of a pain.
I will also resort to heavy gauge wire to tie between the grounds on the circuitboard and the negative terminals on the in and out jacks, if they are the open frame type and the layout supports it.
Sometimes it helps to just have all of the parts in front of you and play with them, and try to envision how to get them all to fit together in a way that works to your satisfaction.
"Being ashamed of our mistakes turns them into crimes."