It’s okay to place the most important bit of your sketch dead center.
If there’s a reason to do it, that is.
In this point-of-view sketch, it made sense to have my lovely-looking margarita be right in the middle of the page. It sat right there, in front of me, being refilled often from that jug all evening. The food and friends were my supporting elements, I guess…(but don’t tell them that!)
Dead center and bilateral symmetry doesn’t create much movement but it is useful in making a piece look balanced and even formal.
I think when you hear “never do (fill this space with whatever ‘rule’ you are presented with)”, it’s just shorthand for “don’t do that unless there’s a very good reason to”.
Or at least that’s how I see most rules…