I wouldn't worry about hitting the side of the ball. What I see in that Verdasco video is:
- set-up semi open
- outside leg behind the ball
- some leg bend
- shoulders turned
- get the racquet head below the contact point for the ball
- keep you head still and eyes on the contact point
- use the kinetic chain to whip the racquet head up through the contact zone
I'd also personally add get your wrist and forearm in a neutral position and don't let the backswing go too far back. Verdasco hits the neutral position but he doesn't dwell there at all so it's hard to see. It' more pronounced in other player's swings.
The more you can rip the head up through the contact zone, the more topspin you'll get. I wouldn't worry about hitting the side of the ball.