So try not to think about bases this and guides and figures that. your task when drawing a sprite is to get as much information as you can into a set sized area. the JRPG's that came out during the SNES era particularly from Squaresoft at the time all had rather similar proportions and headsizes and such. Theyre good to learn and study to see what about them works, but ultimately using them or someone elses base is only going to make your work look like theirs.
If youre a figure drawer, youll know intimately that the human figure has a lot of curves and complexities to it. You dont have the luxury of space to illustrate them, so you will have to suffice with suggesting those forms with a pixel or groups of pixels. If there is a thin outline between one shape and another, it would be wise in a sprite of this size not to draw that outline, but rather let either color or value separate the two shapes.
Note that large vertical lines will tend to make your character look unnaturally stiff. The best way to counter this is to get some asymmetry in your stance and having the arms contour outwards away from the body a bit. Your feet and hands dont have to be that big, it will look more natural for the bulk of the mass to be concentrated in the head/shouders and torso.
Its not easy, it certainly takes a lot of experimenting and adjusting. Save out several different stages of your progress if you find that you are drastically shifting your sprite's pose or proportions, that way you can open them up afterwords and compare them to see which direction you are most happy with. Ultimately theres no 'right' way to go about it, so long as your end result looks natural. Someone else can come into this thread and do some other proportions that may look completely different but still feel entirely correct. youll have to find your own personal style and preferences through lots of practice.
