Here are some tips that will help you in playing one-on-one defense at a hockey match:
Stay Between the Forward and the Net
When you are playing defense in the game, do not forget the basic principal of being between the opposing player and net.
Keep Him to the Outside
As soon you notice a hockey player of opposite team getting into your zone with the puck, try to keep him outside and towards the boards as the chances of scoring from outside are less than the ones from inside. Position of your body plays an important role in this. If the player is coming through the middle of the ice, stand in front of him.
Own the Centre Lane
If the player of opponent team is coming on the wing, always line up slightly towards the centre of the ice. Your position should be in a manner that your shoulder is more or less lined up with the inside shoulder of opponent player. This will encourage him to beat you to outside, the area where he is less of a threat. You should always picture a wide imaginary lane down the middle of the ground and make sure to keep another player out of this lane. The trickiest part of this posture is to control the amount of space or the gap developed between you and other player.
Control the Gap
A too wide gap will allow the forward to cut inside or it might provide him enough space to get close to the goalie by using you as a screen and make a goal. Do not let the gap become wider than two lengths of hockey stick.
If the gap is too narrow, he might get around you if you are unable to keep a check on him.
Watch Their Hips
It is tricky to play one-on-one hockey against an experienced puck carrier as he always looks for a chance to get you out and score the goal. Watching their hip movement will prevent you from getting deked out in your own zone.
An experienced forward player will try to fake you by changing speed, his head, shoulder or other movement. The moment you will focus on his chest of jersey, he might even deke you with entire upper body. So, keep the puck in your peripheral vision and don't stare at it.
The player will not go anywhere without his hips and hips can not be dropped like a shoulder or other parts. So, keep a watch on his hips but not the puck.