When writing a blog, social post, or article - be certain to slow down to check and double-check your spelling and grammar before hitting the publish button.
That sounds elementary, but it's easy to read your work how you want it to sound - and miss mistakes.
Being that spelling and grammar are noted in Google's Quality Rater Guidelines gives insight that this could be a ranking factor. We certainly know other quality factors impact ranking...
There are a ton of great spelling and grammar tools out there, we use three for everything we write! Search them out, read reviews, and buy one - it's a worthy investment.
Beyond technology, we always recommend against publishing on the same day you create something. Instead, wait a day or two; you are sure to make some edits. And be certain to read your words aloud - if it doesn't sound good when spoken, it will not sound any better when read.
Lastly, if you aspire to be a grammarphobe, pick up the book Woe Is I - which uses humor and clever examples to explain grammar in an easy-to-understand - if not a fun way, unlike all the online tools.
This has been my go-to since the first edition, which I borrowed from my mother (a retired English teacher).