1. Create another "management" AWS account, and make your other AWS account a child to that.
2. Ensure no one ever logs in to the "management" account, as there shouldn't be any business purpose in doing so. For example, you should require a hardware key to log in.
3. Configure the "management" account to force children account to enable AWS Config, AWS CloudTrail, etc. Also force them to duplicate logs to the "management" account.
Step 2 is important. At the end of the day, an organization can always find a way to render their security measures useless.