I wrote some jQuery to generate all the 'mw-ui-button mw-ui-big mw-ui-constructive' button variations.

On https://www.mediawiki.org/ and http://ee-flow.wmflabs.org/ ,
if you edit your User:<myname>/common.js and add to it
importScript( 'User:Spage/agoraPanel.js' );
then save and shift-Reload, then in the left-hand navigation area you should see a button that inserts a whole mess of Agora buttons, and also some checkboxes to load button CSS modules.

Let me know if you have problems and feel free to improve it.  This isn't to take away from the living style guide (now in core!), which will guide people in using buttons well, it's just a tool to see them all when developing LESS/CSS.

=S Page  Features engineer