Here's a video and some still pics of one of my favorite swings out there, Mike McNary.
The one thing I think many can learn from Mike is that his swing is pretty slow and deliberate. On the downswing it steadily gains steam, but not until impact. Without question, his lag pressure gets built up and reaches its maximum at impact or shortly after impact.
Watching McNary's swing one never gets the feeling that he's trying to actively get clubhead speed at the bottom of the swing, but it feels like it's a swing that naturally gets a ton of leverage and of course has a metric assload of lag pressure and those sort of go hand in hand.