Hi! I'm making a 2D sidescroller with a tin soldier theme and I've tried to create a sprite for the main character but I'm not satisfied with the result. I want it to be with realistic proportions rather than something cute and round with oversized head and here are my two attempts:

Before these sprites I draw them fully in metal colour but I soon discovered that it's difficult to draw metal so I drew them in a painted uniform instead. I will of course make them face sidewards in the game but for now: how can I improve these sprites?
As I see it the more pixels you have the more better you have to be. With higher resolution you need to know what you're doing otherwise it will look awful and that's why I stick to 32x64 or 64x64
The sprites are ok when you're happy with them

If not, you need to invest some time and optional some money. First off I would recommend to get a proper painting tool like
(free) gimp (currently it looks like mouse painting with MS-Paint). Then I would recommend to paint acutally in a much higher resolution (i.e. 256x256), preview it with 25% zoom and scale it finally down, this leaves you with much better per pixel control. And get rid of the mouse and buy a tablet, thought this will cost around 50-70$ (wacom bamboo), but this investment is really important if you want to get some decent art done.
And finally, what ever way you choose, you need to practise,practise, and practise.