Automating social media sounds like writing a script that posts for you. In practice, the platforms decide what you are allowed to automate, and the wrong approach can get an account restricted. So start with the rules and pick the method second.
The safest method is a scheduling tool that already has an official agreement with each platform. Buffer's free plan covers three channels and lets you queue ten posts per channel at a time. Tools like this handle the approvals, token refreshes and format changes that break homemade scripts. For most small businesses, that is all the automation they need.
The second method is the official APIs. Instagram publishing works through Meta's Graph API, but only for professional accounts, meaning business or creator, and Meta caps how many posts an account can publish through the API in a rolling 24-hour window. X has a free API tier with tight limits, and its Basic tier is listed at $200 a month. That price alone rules out X scripting for many hobby projects.
A good script built on these APIs does the dull parts, not the creative ones. It can pull new blog posts from an RSS feed, draft a caption from the title, resize an image to each platform's specs and put the result into a queue for you to approve. Keeping a human approval step is worth the extra minute, because a broken feed can otherwise post the same link twenty times.
The method to avoid is browser automation that logs in as you and clicks buttons, along with unofficial libraries that mimic the mobile apps. They break whenever the site changes, they require storing your password somewhere, and platforms actively look for them. The same goes for automated follows, likes and comments. Those are the behaviors platforms treat as spam, and they are what get accounts suspended.
Also check each platform's rules on duplicate content. Posting the identical text across many accounts at once is a common trigger for spam filters, so vary the wording by platform.
The short version: use a scheduler for posting, use official APIs only when you need something a scheduler cannot do, keep a human approval step, and never automate engagement. The time you save is not worth an account you cannot get back.
