Dan Replies:
Dear M: To be a defensive forward, in the defensive zone you need to stay on a line between the defenseman on your side of the ice and the goal if the play is down low. If the puck is successfully passed to him, you need to pressure the puck. If the puck comes around or along the boards on your side of the ice you need to develop the skill to get the puck out of the zone - every time. If the defenseman collapses on you, get it past him out of the zone without fail, period. If he doesn't collapse on you, you must catch the puck and begin the break out.
If the puck is in the offensive zone, while it's important to play offense, you must always be ready to switch to playing defense if the puck gets turned over or is about to get turned over. If your opposing winger doesn't have the puck, you need to stay with him, preferably between him and the puck. By staying with him, I mean if he skates like a bat toward your goal, you skate with him all the way to the goal and stay with him until your D can get set up.
On face-offs in the defensive zone, you have a defenseman to cover. When the puck is dropped you streak out to cover him. Then you'll be in the right position to continue the break out if your centerman wins the draw.
The best advice I can give you is to watch your man not the game. If you watch a NHL winger who is conscious of his defensive role, when the puck is in the defensive zone his head will be on a swivel: watching the puck for two seconds or so, checking on his defenseman, watching the puck, checking his defenseman, etc. While it's more fun to watch the game, if you are assigned the role of defensive forward it's more important to watch your opposing winger if there is a turnover or about to be one or the opposing defenseman if you're in the defensive zone.
To be a good defensive forward, you need always to be thinking about what you're doing and anticipating what may be happening next.
Lastly, you need to take pride in your role. Determine that your team will not be scored against on your shift and work very hard to make that happen. A lot of people think that the sign of a good hockey player is what he does with the puck. But you only get a chance to be good with the puck for 15 - 30 seconds in a game. A knowledgeable hockey person knows that what you do when you don't have the puck (19+ minutes) may have more to do with the outcome of the game. Because if the other team doesn't score, they don't win.
Don't lose sight of the fact that every forward is responsible for defensive play. It's just that offensive forwards and defensive forwards have different mentalities; an offensive forward will take chances if he thinks there's a chance to score, a defensive forward plays more conservatively and will look to make the safe play, realizing he's on the ice against guys with the skills to capitalize on any mistakes.