for small icons and other small things, I used this blog:

For the bg in resources: 

and for the other art;
I mostly found them on pinterest, although they seem to be taken from tumblr. Here's what I was able to find.

and all the other links I found:
https://www.asterism-m.com/item/icon/
https://web.archive.org/web/20100210185751/http://neskaya.net/

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new years decos:
http://pixel-kitten.tumblr.com/tagged/season

https://kawaii-pixelprincess.tumblr.com/tagged/pixel
https://wifflegif.com/gifs/623725-christmas-pixel-kawaii-stuff-gif