Host-based pillars

Hello, How can assign custom metadata to a host? (custom key/value pairs for example) I know I can define a pillar manually in Salt master /srv/pillar. However it would be great to just be able to assign custom values/pillars to a host in the GUI such that I can pick those up in my states. I know I can include this myself in the GUI by using forms. But that's not what I mean because I would have to "ask the same question" in every form where this information is required. Instead, I just want these custom attributes derived from the host, plain and simple. Any idea? Thanks.