Personally, I never use the "skateboard" example because folks plant the right foot and never move it forward essentially becoming the "sun" while their partner revolves around them. Think about it...when you use a skateboard the only foot you move is the left one...the right one is on top of the skateboard and you, personally, don't move it.
My approach is after a short explanation about ballroom position and with the dancers in that position I introduce the buzz step after the walking swing. AFter a short demo, I say, " Put your right foot in front and think about "galloping"". (most folks remember that from grade school). "Ok ready? Gallop." while I deetle, dum the "The Lone Ranger" aka "The William Tell Overture". This really works! Folks can gallop to "The Lone Ranger" faster and easier than a reel. And it brings a smile to their faces.
Most newcomers get it the first time through. Occasionally I have to work with someone with a 2 hand turn so they get the idea and then move into the ballroom hold again.
If I had 2 minutes for a lesson, I'd do walking swing, buzz step swing, and address dizziness and techniques to minimize that and encourage new folks to dance with other people.
In my first dance I would teach allemandes and giving weight to the entire room as well as talking/teaching through each and every move I introduce and address safe hand holds. A few words, not a lecture. If necessary I also remind experienced dancers to use gestures not words when helping a new dancer.
BTW: I strongly believe that teaching does not stop when the beginner lesson is over. I usually talk/teach every move in the first couple of dances as a rule. It takes seconds to say, "Ladies chain, Ladies give right hands to each other and pull by, give your left to the gent and Gents put your right hand on the ladies back and courtesy turn with Gents backing up and ladies going forward. And then you give necessary information to the new dances who just arrived (and missed the lesson) as well as the 2nd or 3rd time attendees who may need a refresher (and missed the lesson).
Contra dancing uses a foreign language with vocabulary that must be learned. We're the callers, I believe we should be the teachers as well.
Donna Hunt