Andreas Thaler
Subscriber
There are screw extractors for watchmaking but they can't be used on cameras most of the time since they're very small.
I can recommend this screw extractor for screws M1 ~ 2.6:



The last option that works well for me is the Dremel with a tungsten carbide tip for milling out screw heads.
The remaining screw residue can be removed with these pliers, the Nejisaurus:

