Say you want a card to reference a different list/checklist/card/etc. depending on the label attached. Normally you'd have to make multiple rules due to the inflexibility of Labels in Butler but..
The first thing to note is that when you filter for "a green label", an option that is available so long as you have a blank green label, no matter how many named green labels you have, it will filter for any green label, even the named ones.
The second thing to note is that triggers that filter, such as "when a card with a green label is moved in to list X", you can access the label name via {labelname}, which would be different depending on which green named label was attached.
From there, you can Find a card name that starts with {labelname}, or add it to checklist "{labelname}{*}", or move it to list {labelname}.
Allowing for a single rule that extends no matter how many labels you create, needing a lot less maintenance. Downside is they're now all green of course..
Hope that helps someone fiddling with Butler. Or share other tricks and tips you've happened on along the way with Butler.
(small) Collection of other Butler-hacks