Have a Quick Start and a Big Finish

"Ready when you are C.B."
-   doomed cameraman

From IMDB:

Cecil B DeMille is the subject of many Hollywood legends. According to one famous story, DeMille once directed a film that required a huge, expensive battle scene. Filming on location in a California valley, the director set up multiple cameras to capture the action from every angle. It was a sequence that could only be done once. When DeMille yelled "Action!," thousands of extras playing soldiers stormed across the field, firing their guns. Riders on horseback galloped over the hills. Cannons fired, pyrotechnic explosives were blown up, and battle towers loaded with soldiers came toppling down. The whole sequence went off perfectly. At the end of the scene, DeMille yelled "Cut!" He was then informed, to his horror, that three of the four cameras recording the battle sequence had failed. In Camera #1, the film had broken. Camera #2 had missed shooting the sequence when a dirt clod was kicked into the lens by a horse's hoof. Camera #3 had been destroyed when a battle tower had fallen on it. DeMille was at his wit's end when he suddenly remembered that he still had Camera #4, which he had had placed along with a cameraman on a nearby hill to get a long shot of the battle sequence. DeMille grabbed his megaphone and called up to the cameraman, "Did you get all that?" The cameraman on the hill waved and shouted back, "Ready when you are, C.B.!".

One of the great arguments in instructional design is the battle of form and function.   Many designers will argue that the content is king, and everything else is secondary at best and irrelevant at its worst.   I know one colleague who refers derisively to anything that isn't pure information as "useless sizzle."

But I disagree.  I don't think you can have a real learning experience if it isn't memorable.  And it won't be memorable if its boring.  You can have the greatest message in the world but if you can't hold your learner's attention you simply fail.

So I will leave you with two insights from another colleague:

1. Get them doing something interesting -- even if it's just a group discussion -- very early. Don't bog them down with YOUR long introduction, the history of the topic, etc. The faster they're engaged, the better.
2. Don't let the class fizzle out at the end. Try to end on a high. It's like the movies... where they usually put the best song at the very end, during the closing credits... because this often determines the feeling you leave with. Ask yourself, "what were my students feeling when they left?" 

Think Big.

Design Big.

Be Memorable.