Sheet hold-down

[346CADmen]

Magnetic tables work well, but are pricey. With sheet you can use ferrous material (scrap) to hold down your non-ferrous. May not be viable for your team, but you asked for options.

[jijiglobe]

for holding down the edges you can use Cleco clamps

They come in some Cleco sets and you can open and close them with Cleco Pliers They're nice and small so you can get them into places where there's really low clearance.