Plank is a great base for so many asanas which require core stability and strength in the arms, like Chaturanga Dandasana, Bakasana, headstands and even handstands. Planking every day can be very beneficial in building power in your core and stability in your body and can be done every day, on and off the yoga shala mat (at home, in your office etc.).
Don’t - the slouching plank
Plank is a very strong position in which you should feel your whole body should be active. If it isn’t, this can be a result. Gravity does what it does and, if we don’t pull up, it will pull down like in the photo on the left where the head is hanging down, as well as chest and hips resulting in this banana shape plank.
Do - the neutral plank
Lift the back of the head as you want to touch the ceiling, push the floor with your hands, engage the abdominal wall to lift the hips, activate gluteus (booty) and legs.
This is a more neutral plank, which means that, if we look at it sideways and turn it on the feet, it resembles Tadasana (the most anatomically neutral asana) with arms forward. For more power in the core you can try the variation below.
Do - the strong plank
To access more power in the core, arch your back a bit more, creating a flexion in the spine and activating abdominal muscles more as it takes more effort to pull away from the gravity. You will feel the activation of your anterior chain (muscle groups lining the front of your body) muscles more than the posterior, but the back muscles are also working hard to stabilise the position.