Ten minutes a week is enough when the setup is right.
Busy leaders rarely lack ideas. They lack a routine. Here is a simple one.
First, keep a running list of topics: moments from meetings, questions people ask you, lessons you repeat.
Second, set aside one short slot each week to review the drafts. Read them out loud. Change anything that does not sound like you.
Third, approve and schedule. Once a post is approved it should not need you again until you read the replies.
Finally, look at what worked once a month and bring the best posts back. Good ideas deserve a second airing.