Study real people walking! NOT Final Fantasy.
I don't mean to sound harsh but the 4-frame slide-walk that's used in so many old RPGs is long, LONG outdated and needs to be retired. You can use the same amount of frames and have a much more convincing walk if you put a little more effort in. Bend his knees, and don't try to re-use the standing frame by putting it in the walk cycle, there is no point in a normal human walking cycle where it looks like they are standing with both legs straight and flat against the ground. In fact trying to make the movements your character is making is not physically possible, unless you're slipping on ice or something like that.
And whatever you do, banish Final Fantasy from your mind; the animations in those old RPGs weren't done that way because they look good, but rather because of a lack of processing power.