The following two poses, Titthibhasana (Firefly) and Bakasana (Crane/crow pose), are the dynamic duo you have to flow through when you are transitioning out of Supta Kurmasana (sleeping turtle), the Gordian knot of Primary Series.
Exhale, from Supta kurmasana, move your hands underneath your shoulders. Inhale, press into your hands, lift your hips and feet away from the floor. Keep your ankles crossed behind your neck. Once you are balancing on your hands, still inhaling, straighten out your legs, dropping your hips and lifting your feet. Look forward. Hold for the duration of the inhalation (or longer if you want to build strength for Intermediate).
Exhale, pull your heels back to your bum. Press your arms straight, drop your tailbone, suck your heels up to your bum, and press through your index knuckles. Squeeze your knees into your arms. Look forward. Now you are in bakasana. Hold for the duration of the exhalation (or longer if you want! The first westerners to practice Ashtanga would hold this pose for up to 59 breaths!). Then, inhale, followed by an exhalation, jump back into chaturanga.
Both poses are excellent at developing arm strength, endurance, and focus. Make sure to straighten your arms as fully as possible. Work on smoothing out the transition from one pose to the next. If you practice Crow with bent arms, you will only get strong in that particular joint angle.
And don’t forget to soften your face and breathe!
Let me know if you have any questions.