Probes or "Spudges": Chop Sticks

I have found that plain old chop sticks are great to poke around in chassis to find bad connections, loose parts, etc.

 A dab of wax from an old wax capacitor to the end of the chop stick can let you retrieve that tiny screw back in the corner of the chassis where it fell. 

It can also hold a nut in place until you get it started on the bolt or machine screw.

 Best of all, they are "free" after you finish your bowl of noodles. Just wash & use.

I have also cut down popcicle sticks or tongue depressors to make a square ended core adjustment tool for certain radios.