If you need some inspiration here's a project I did a while back.
https://forum.tz-uk.com/showthread.p...d-shotgun-case
You could look at using something like Sikablock modelling foam if you needed to mount watch cushions for watches with bracelets.
Edit: and this one:
https://forum.tz-uk.com/showthread.p...d-writing-case
In the Sotadic Zone, apparently.