Working against the knife
Ideally it is preferable to use a real knife for training, but this should be dulled for safety. Otherwise you can get a purpose made metal training knife. This will offer the best compromise between realism and safety.
Unlike unarmed training it is preferable to start training up close and then increase the distance as your skill improves. Due to this start training with the knife against the body. That way you can feel the direction of the knife and educate your body to get out of the way.
It is useful to let your partner poke you with the knife. This should be done slowly to allow you to feel the direction of the knife and move the appropriate part of the body out of the way.
Against stabbing attacks practice moving out of the line of attack so that the knife continues in the direction it is heading.
Have your partner cut and stab slowly and fluidly. Move around him escaping the cuts. When the blade makes contact with the body move so that it escapes and lessons any potential damage. Try to use your movement and not your hands to avoid the blade.
Practice disarming your partner when he holds you by one of your wrists and attacks with the knife at the same time. Limiting your movement in this or any other manner will teach you to move and react creatively.
Other ways you can use to limit your movements are to tie a hand behind your back, work from a seated position or with your eyes closed. The number of variations to these drills are only limited by your own imagination.
Like all work start slowly and take your time. Do not be to greedy with your progress. Learn to react calmly no matter what the threat. Donít snatch at the knife, work against the person wielding it instead.
Practice using your environment and clothing to your advantage. Move so that chairs and other furniture provide a natural barrier to you attackers movement. Understanding the protection provided by your clothing will help you move appropriately.