Humans are not meant to multitask and switching tasks can be costly. It requires a lot of mental energy and often a lot more time to prepare for task execution. This is the reason that doing the same or similar tasks all at once is so beneficial.
Plan your week in such a way that you can do the same type of tasks at the same time.
For example, if you want to publish four blog posts, write all of them at once. Do all of the accounting tasks once a month and so on.