HERE is the parent suggestion thread! This threads theme is GREATSWORDS, which will also share skill tree aspects with Great Axes and Great Hammers, so if you have ideas for those, drop them there as well!
I'll also check the comments here if there are any, so if you don't have a Reddit account, don't be discouraged! (:
Remember, I don't care how pointless, stupid or specific the skill is - So long as it's fun, that's all I care about! (And that it's not insanely complex, of course haha)