Any advice on saving space on a Windows 8 install?

Have you gotten rid of the stock apps on the Metro Screen?

 

Turn off hibernation, saves as much space as the installed RAM

 

Remove the recovery/backup files, should clear up a couple of gigs. I personally have not done this but it is apparently something you can do easily. The kicker is if you ever have to reinstall/refresh Win 8 you cannot do it easily through factory restore in the settings but instead have to do a fresh install after a format.

Disk Cleanup is nice however typically the stuff that it clears out (mostly temporary files) usually amounts to about 100 MB. From time to time due to a restore or an update to Windows itself something might get a backup performed on it resulting in a XXXXX.old file or folder. Disk Cleanup will knock these out. AS an example if you ever use the restore/refresh options in settings to "factory reinstall" just Windows it will backup all your Windows settings/files in a .old and reapply some of them. Afterwords the .old needs to be removed.

Like ErikvanD mentioned you can also dial down the size of the page file as that should be about 1-2 GB based on the amount of ram you have. Another good tip would be to remove all the drivers you do not need or use. Windows is packed with tons of generic drivers for all sorts of devices and if you have no need for them why not blow them away. Same goes for help files and documentation.