I have only one good spot on my workbench and I came up with an idea to make the most out of that spot. Modularize it (I played with a lot of legos when I was a kid)!
The basic Idea is to attach your bench grinder, vise, miter saw, Belt sander, etc. to a board that you can freely clamp to your workbench.
Step 1: Mark and Drill Holes.
Get a board slightly larger than your device, so that clamps can easily be applied to the back and sides of your device.
Get the correct length bolts and countersink them in the bottom so it will be flush with the workbench. I used a large drill bit and chisel to get the right space for the counter sink hole.
Step 2: Test the Fit
Insert bolts and test that the device fits properly.
Some ideas, I've not tried yet, Epoxy the bolts once tested. Add some padding to the bottom of the board.
Step 3: Tighten the Device to the Board.
That's pretty much it. Tighten the device to your board.
Now you can use some c-clamps or vice clamps to attach it to your work bench without drilling holes for the specific device.
I tested my vise with some drilling and sawing. Worked perfect.