Sharp sprites when blur after resize[discussion]

[InPhiKnight]

When I make sprites at 400% or something else size, bigger than 79x79..... when I resize them to 79x79 they become blur...too blur.
I just resize them with paint.net and don't sharpen them...'cause idk how to do it in a proper method.
How to shapen the sprites after resize or how you resize them?

Help will be appreciated!