I run a Windows 10 test VM under VMWare workstation and I've noticed that it uses a lot of background CPU/Memory even when it's not doing anything. I'd like as much as possible for this VM to be doing nothing when I'm not using it. I've already disabled Windows Update (which I only want to use manually since I use snapshots) and I've disabled search indexing. Are there any other obvious quick wins from the point of view of getting Windows to properly idle using few resources?
Have you installed the VMware guest extensions? Those help quite a bit (especially with scheduling).
The next VMware specific thing to try is VMware's OS optimization tool.