animation, walk cycle

OK, so today was about creating a successful walk cycle, which I had two attempts at, but they both desire improvement. The video bellow is a line test and my first attempt at a walk cycle, consisting of 12 frames, I had misunderstood the process a little, maintaining mass was a little difficult, overall not that good.

Below is my second attempt and second line test, which has 21 frames. At this point I understood how to co-ordinate my frames while drawing them, which was confusing as I kept loosing track which frame went where.

There is a fair few point to improve on. For starters, I was so focused on the getting the in-between movements on the legs correct I completely neglected the movement of the arms, which will be something to consider on my next attempt. Again, change in mass is an issue, but this is more noticeable in the head, which I think over time and with practice this mistake will happen less often. The bad arm movement really is the downfall of this, so I will simply have to try again until I do it correctly, when I can do this sequence well I would like to apply a design to it, that will make it more fun to do I think.
While an animation like this would usually be at 12 fps, I brought it lower because 12 fps made the movement too quick therefore looked unnatural. When I brought it down to 8 fps and the speed was more believable.