Old pruners and concave cutters that haven't been exactly treated well. Don't really like to use "good" tools to work in dirty, sandy, rocky, soil, it turns the edges bad in a hurry.
Depends on the work. I use pruning saws, bypass cutters and older (but still sharp) shears...
The most useful tool Ive found for rootbound deciduous nursery stock is a hose with a pressure nozzle. Moves all the old soil of easily so I can see what's what before I start cutting. Also removes grit that dulls cutting tools.