Edit UGH. On the theme, I just realized that I forgot to replace my header image with the one of outer space. So now my face will be on every new install. >_< I’m sorry guys!
If you want to replace the header image, 460px wide is the ideal size. You can crop and resize your images here for free.
Edit 2 I also just realized that I left my personal Tumblr link in the code, which you can delete by going to “Edit HTML” and searching for “My Tumblr”, and then deleting the text between that <li></li> tag. Sorry about this; I’ve just submitted these edits to Tumblr, so hopefully they will show up on the new installs now.