So that disk is decent, I'd just do the standard stuff that you already know, disable indexing, create a fixed size pagefile, etc. Then go through Settings, Control Panel & Services disabling everything you deem unnecessary, heh!
To be fair, I've found Win 10 to be decent on low spec boxes, but anyway...
Some Specific Windows 10 Stuff:
Use a Local Account rather than a MS account, doing that will cut out a load of nonsense right there.
Go into Settings->Privacy and disable everything or, at least, everything you don't need. Background Apps is the major hog here.
Settings->Update & Security->Windows Update->Advanced Options->Choose how updates are delivered - disable peer-to-peer file sharing.
Settings->WiFi->Manage WiFi Settings - disable WiFi Sense password sharing.
Disable System Restore.
Startup apps are now disabled in Task Manager.
Uninstall unwanted store apps:
Open Powershell and type: Get-AppxPackage -AllUsers
This returns a list of all the installed apps, you use this to find the PackageFullName of the app you want to uninstall.
To uninstall an app type: Remove-AppxPackage PackageFullName
Using Remove-AppxPackage PackageFullName uninstalls the app from the user account but leaves the app on disk, ready to be installed for other users...
If you go to C:\Program Files\WindowsApps you will see each app has a 'companion' folder with 'neutral' in the name.
If you use the command: remove-AppxProvisionedPackage -package NeutralFolderName -online it removes both folders from disk.
Disable MS Spy Telemetry:
Create a new registry DWORD value in: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\DataCollection
AllowTelemetry = 0
Then disable two services: Diagnostics Tracking Service & dmwappushsvc.
In task manager right-click Cortana and choose 'Open file location' to find out where Cortana's folder is. Rename this folder (add .bak to the name), it will fail and show a 'try again' dialogue, end the Cortana process and quickly press the try again button before it starts up.
From Run or Command Prompt: %SystemRoot%\SysWOW64\OneDriveSetup.exe /uninstall
I'll post anything else of special note if it occurs to me.