Draw the stickman in "contact position," in which the right heel is landing on the ground in front of the character with the right leg in full extension. The left leg is bent back and in the air behind him. Be sure to draw the character leaning forwards into the run, as that is one of the key visual differences between a run and a walk. Also, in each frame, the arms should move opposite the legs, i.e., the right arm should pump back with a fist as the right leg extends forward.
Draw another frame of the stickman in "passing position." This means the leg, left in this case, is in the process of moving past the right leg. Draw the left knee in front of the right leg and the right leg centered below the character's hips. Be sure to have the right leg slightly bent and the stickman's upper body slightly lower in proportion. In the run cycle, the stickman's head and body should appear to naturally bob up and down, and this frame should show his lowest position. Also important is to draw the character on the same part of the paper. Because you want to be able to loop this animation, the stickman should not actually run across the screen. Instead draw the legs as if the character were on a treadmill, with the feet shifting back and the character's body remaining in roughly the same place.
Draw the right leg in full extension behind the body, front of the right foot pushing off the ground as it propels the stickman into the stride. The left leg is still bent and forwards. The body and head position should be slightly higher than the previous frame.
Draw the stickman having kicked off the ground, right leg still straight with foot extended. The arms are both the closest to the body and the head is raised a little higher. Draw the left leg bent with the thigh roughly parallel to the ground as it moves further into the step.
Draw the stickman off the ground with the legs extended by roughly the same degree in opposite directions, right leg back and left leg forwards. This should be the highest position of the stickman's head. For frames 6 through 10, draw the same positions as frames 1 through 5 for the left leg. With a stickman, it is possible to get away with tracing the same drawings over again, but the human eye can recognize the pattern and create a "flicker effect," so it is best to draw them slightly differently. Do use your other drawings as reference, making sure the left foot makes contact in about the same places as the right foot did.