While reading a post the utmost effort of a reader is to walk through it, grasp the desired info and head over as quickly as possible. So, it is important to place the desired info smartly while crafting paras.
In the opening, you should not waste your time in writing fluff. This applies specifically to those paragraphs that aim to narrate a tutorial, fact or some feature. You should directly make your point and then jump over to its explanation.
For opinion-based content, I'll recommend to start with a one-liner background followed by what you think about it and the reasons behind your stance.
For descriptive type of content, you should focus on providing maximum details while using minimum words. This helps a reader to gather all the desired info at one place.
(Note: All these tips encourage you to writing short paragraphs that are no more than 3 to 4 lines. P.S. intros and outros are handled differently. I'll share how to write these in the following chapters.)