First of all, welcome to pixelation.
Well, since an image is worth 1000 words (and more) I just did a fast edit on your hammer.
(While I guess you made a black hammer I took the liberty of making a metallic one.)
Your palettes have really close colors, making your whole image dull (and more because of the color you chose for your background), and this goes for both hammers and axes.
Don't be afraid of using colors with more contrasted tones. Pick them wisely (your hammer had 13+bg colors while my edit has 7+bg).
Once you get practice picking palettes you can take it further and start making your stuff more detailed etc.
Hope the edit helps you.
Good luck