Courtesy costs nothing. Be polite when interacting with fellow bloggers and your readers and your courtesy will be visible in your writing.
Interact with your readers! Reply to their comments, emails and queries. Acknowledging your reader will make them come back to your blog again and again.
Formatting - Your post need not be a circus. If you are not good with formatting, then stick to a theme that is light and descent in colors and the post layout. If you are good with trying new stuff then use that skill to better express through colors, fonts and layouts. Avoid colors that are dark and fonts that are overtly bright.
It was lovely knowing your takeaways from 2017. Now, let us hear your wishes for 2018. Aren't we all looking at the new year with love and hope? It is better to write down and then refer to it regularly if you really care about them.