Surya namaskar is a wonderful series of poses to wake you up, get your energy moving and release some tension.

Begin in Tadasana; with feet together, toes touching heels slightly
apart, really spread your toes, increasing your foundation/support. Feel the ground beneath the four point of your foot (toes and heels), lift up through your body, activating your legs (calves, thighs in particular), but ensure there is a softness in the knees. Keep your abdomen gently contained and feel the spine grow long toward the crown of your head. Your arms and fingers are active by your sides.

Take a few breaths here, and centering and settling into your body. Begin to focus on your breath, and allow it to guide your movements.

Bring hands together in prayer position at your heart.
Breathing in, lift your hands up through the centre line of your body, above your head. Take the gaze to your thumbs.

Breathing out, take your arms wide, bending at the hips and leading with the chest, swan dive down towards the ground (uttanasana). You might like to keep your knees softly bent (this helps reduce pressure on the lower back, particularly whilst your muscles are warming up). Keep your gaze at your knees, and take the hands either to your shins or to the floor (wherever can reach).

Breathing in, place your hands on your shins, gently arch your upper spine and gaze up towards the ceiling (ardha uttanasana).

Breathing out, release back down, gazing once more at your knees.
Breathing in, lunge your left leg back, making sure your front knee is in line with your ankle.
Breathing out, take right leg back to meet left (hip width apart), - into plank position (adho mukha purvottanasana - keeping your body in one straight line from your toes to the crown of your head)
Breathe in, and as you breathe out, drop the knees to the floor, your chest between your hands, and your chin also rests on the floor, this is 8-point pose. If you’d like a slightly stronger variation: gently lower your body from lank towards the floor. Keep your elbows tucked in, and stay about 1 inch from the floor; chatturunga dandasana.

Breathing in, move your weight forward, rollover onto top of feet and come forward into urdhva mukha svanasana, here your upper back is arched (its important not to collapse through the lower back), your hips and thighs are off the ground and your gaze is upwards, towards the ceiling.
Breathing out, drop knees to floor, shift back onto your toes and push up into adho mukha svanasana (downward dog); become aware of the floor beneath your hands, each finger, and in particular under the first knuckles. Your head is relaxed, in the space between your arms, and you lift up toward the hips, allowing your sitting bones to reach towards the ceiling. Feel length coming through the backs of your legs, the hamstrings and calves and your heels draw down towards the floor. Keep a softness through the knees and elbows rather than locking them.
Enjoy 3 breaths here.

Then breathing in, take your left leg forward between your hands - into a lunge. Bring your right leg up to meet your left.
Breathing out, allow your hands to rest either on your shins or on the floor (uttanasana - forward bend) and your gaze is to your shins.

Breathing in, take your arms out wide as you bring your body upright into a standing position, your arms finish above your head, your hands is prayer position (reverse swan dive)
Allow the hands to float down through the centre line of your body back to your heart centre.

This is one side. Now repeat the same sequence lunging back with the other leg.

Always finish with a few minutes of Savasana (this is the best part).
Lying on your back, feet flopped out to the sides, arms by sides with palms facing up, close your eyes and allow each part of your body to relax

Enjoy this sequence whenever you want a little energy, a release or your body needs a little more flexibility and openness.