Don’t spread yourself too thin! So many people try to be on every website. That’s not useful if you’re only posting there once a week. You need to choose up to three places where you will be active and post there at least daily!
Don’t let social media take over your writing time too much! There are many ways to deal with this:
Put a timer on for 20 minutes and once it goes off you’re done with FB and Twitter. Turn off your internet and go write!
Don’t do the social media work yourself at all! There are people on fiver etc that you can pay to make professional material and post it for you. This won't work for everyone, but there are many who are trying to pull together their career by their bootstraps and don't take the time to consider this option.
Consider taking two hours at the start of the month, throw on a podcast, and make/schedule all of your posts so that you don’t have to worry about it again until next month!
Don't make random material to post online! Your goal is to connect with readers, and then ask them to buy your book. Post about things that you care about and things that they'll care about.