I don't have a workflow as such, but being a programmer, I've tried to automate as much as I can through AD group policy and scripts. Most weeks I don't have to spend any time managing them. We're a biotech company so people here are mostly non-technical (IT) and rarely install random software, etc..

Security: I lock down most machines so that they can only run executables from certain directories, streamline windows updates through GPO, strict firewall rules, etc. At the router level, I use cisco's meraki service, which manages VPNs, content filtering and router firmware updates, etc for me.

Machine Management: I use RDP if needed. I have a 'request support' script that sends me a message if anyone needs anything.

Machine Imaging: I have a clean W10 sysprep-ed image with our LOB software, office 365, etc. I have a deployment script that sets up the partitions and images the machines, etc. I'm looking into getting Intel's ME for our office so I can do that over the network without physically going to the machine. We have two locations and its a pain if I have to physically go to the other one.

Storage: We have networked drives for every user and those get backed up every day through veeam, along with all of our VMs, etc.