no shiplap, ever.

faux beams only if they are positioned where real support beams may have been.

Look at the structure of the room and see where the most logical placement should be.

Here are a few photos that may help you decide the look you like best.

Thank you for those examples ffpalm. They’re helpful to visualize.

How ironic to come across your ask just after someone on another thread suggested 8th ceilings were a horrific thing and here you are trying to lower the feel of your ceiling. Are you thinking just beams like the pics above or more trusses look? Maybe your space is too narrow for trusses. Since you have so much white already I would go with beautiful wood. Really make them a beautiful feature. The wood will bring down the feel of ceiling height more than the white will. The thing with the wood in the future if you really need a switch up they can be painted out.