Here's an advanced way to get the benefits of the plank while also hitting the traps, deltoids, lats, and other surrounding muscles. It's called the single-arm plank press.
This awkward variation forces you to stabilize the body through one arm, all the while preventing rotation, keeping the hips high and tight, and the upper body locked to limit the lateral shift that would happen while performing a contralateral press.
This exercise demands spinal endurance, spinal stability, core endurance, and core strength along with the muscles of the lumbo-pelvic hip region.
Also, if you lack strength in the neck and hips because of sitting and texting all day, this variation can help prevent nagging pain by keeping efficient energy and awareness around the localized muscles.
Throw this variation of the shoulder press into your program. It'll teach you how to properly apply tension throughout your body and breathe properly, while at the same time targeting the muscles in your upper body.