Taicih Walking is the most fundamental stance in Taichi Routine. It provides a stable base from which to absorb or express force.
Hopefully my in-person instruction or online illustration will give you a good understanding of the steps. With your own practice you can be proficient walking in this way for the Tai Chi routine you are working on.
Lets start together from a right standing lunge posture, as shown in Step 0. The front or right foot is pointing straight ahead with majority (60-80%) of the bodyweight resting on it. The shin should be perpendicular to the ground (with the weight carried by the large bone of the tibia in the lower leg and pressing directly into the heel). The back/right leg is firmly set into the ground while supporting the remaining bodyweight. The knee of the rear leg is slightly bent, or say the right leg is naturally extended. The toes of the rear/right foot are pointed out at 45 degrees. The head and body are upright and perpendicular to the ground. In Tai Chi, the stance is called Bow Stance. More specifically it is called right bow stance since the right leg is in front and sustaining majority of the body weight. The footprint should be the same as shown in step 0.
Shifting the bodyweight onto the left leg, turn the right foot out at 45 degree. Then transfer the bodyweight back onto the right leg (1R). Then lift left foot towards the right foot then step forward. The left heel was placed down and touch the ground first. As the bodyweight pours forward, the toes are placed down. Then the majority of the bodyweight was transferred and settled on the left leg firmly. Left Toe should be pointing straight ahead (1L). The footprint should be the same as shown in Step 1.
As we keep going, Shifting the bodyweight onto the right leg (1R), turn the left foot out at 45 degree (2L); Then transfer the bodyweight back onto the left leg; Then lift right foot towards the left foot then step it forward (2R), pointing straight ahead. Heel touches the ground first then toes then gradually shift the bodyweight to the right leg. The footprint should be the same as shown in step2.
Shifting the bodyweight onto the left leg, turn the right foot out at 45 degree (3R). Then transfer the bodyweight back onto the right leg (3R). Then lift left foot towards the right foot then step forward. The left heel was placed down and touch the ground first. As the bodyweight pours forward, the toes are placed down. Then the majority of the bodyweight was transferred and settled on the left leg firmly. Left Toe should be pointing straight ahead (3L). The footprint should be the same as shown in Step 3.
When stepping forward, make sure that the knee stays behind the tip of the toes. Because the load on the knee increases dramatically beyond this point and so it is best avoided. Your posture may also become more unbalanced. The knee of the back leg should be pointing in the same direction as the toe.
When shifting bodyweight between legs, carefully pour the weight forward being prepared to reverse direction at any moment. The bodyweight should ideally pour into the heel of the front foot, but never more forward than the middle of the foot.