This is not exactly a ground breaking tip, but...
I've found that if you are working on a machine and have to unscrew a few things to get access to the place you are working on then if you have a spare one of these rubber feet:
www.pinball.co.uk
they make excellent receptacles for holding the screws. You can put the rubber foot on the glass of a neighbouring machine and it won't slide off.
Ithankyou
I've found that if you are working on a machine and have to unscrew a few things to get access to the place you are working on then if you have a spare one of these rubber feet:

Rubber shoe for bottom of pinball leg (set of 4) - Pinball Heaven
Rubber shoe for bottom of pinball leg. This great little accessory stops a LOT of noise transmission on solid floors and protects the floor from the weight of a pinball machine. Sold in sets of FOUR!

they make excellent receptacles for holding the screws. You can put the rubber foot on the glass of a neighbouring machine and it won't slide off.
Ithankyou