Pause and resume the download
Restart Steam
Restart your PC
Check your internet speed
Use a wired Ethernet connection
Stop other downloads and streaming
Close bandwidth-heavy apps and browser tabs
Change Steam download region
Clear Steam download cache
Limit or remove Steam download throttling
Disable VPN or proxy
Update your network drivers
Change your DNS server
Set Steam to high priority in Task Manager
Make sure your drive has enough free space
Install games on an SSD
Temporarily disable antivirus scanning for Steam downloads
Check for Windows updates
Reboot your router and modem
Try downloading at off-peak hours