If you're sick of the spacing between images in your blog posts then you can follow these steps to manually adjust the CSS settings for your images.
Remove Spacing Between Blog Images With CSS
Things to Know
This will only apply to images set with Alignment None or Alignment Center
Hard Returns between images will still leave spaces, be sure you're not adding returns between images.
This isn't a perfect science...so give it a try and see how it works.
If you are looking for more ways to alter the format of your blog design, check out this article here.