Move your body away as the person with the knife comes at you and leave your arm behind (where your body was just now). Use it to drape the flat of the blade on your body and check where it works for you to place your arm and how to work differently from different places as it will not always work as you want it to. Make a note to pay attention when you are in a safe distance where the partner has to step toward you or to throw the knife to reach you and where he only has to reach with his body (twist/turn) or raise the arm to reach you. Make sure you pay attention when and where you control this distance and how it changes all the time. Avoid measuring according to the distance between you and somebody because it makes you dependent and you are leaning on his location. Place yourself in space.
take a not too sharp a knife or a pencil and stab your partner swiftly. When you work slowly many times you will lie to yourself and let it sink a bit before you move. You need to be aware of your movement all the time (breathing) and choose your action in a way that doesn’t come into the blade. Move to a sharp blade if you are comfortable enough and know your partner and work slowly on this same drill. Work with your back to the wall to learn to move away without tensing the part that is targeted. Work as your partner moves the tip of the blade or the edge into your body or arm after the first contact and check what works for you to control the movement.