So I'm constantly bothered by designing blogs and the date header and the post title have a huge space between them. Well I just learned how to decrease that space and wanted to share a tutorial with you guys.
The first thing you want to do is click on "template designer" it should bring you to a page that looks like this:
Then click on the "advanced" bar in the far left hand corner of the screen as seen below. Then scroll down the entire list to where it says "Add CSS":
Post this code into the CSS box, then go to the end of the code and press the space bar to see it take affect.
margin-top: -25px !important;
If the space is still to large for your liking simply change the -25px to a larger negative number e.g (-30) or contrarily if the space is too narrow simply make it a smaller number e.g (-10). If you like what you see simply click on "apply to blog" and then "back to blogger" to see your new post look.