Here are some essential guidelines for pranayama to start your practice of pranayama at home. These are guidelines are for reference only and people can modify these as per any specific condition in consultation with their yoga teacher.
It is recommended to do pranayama early in the morning, one to two hours before sunrise when oxygen content is maximum in the air. Also, early morning body is fresh and mind is clear from any thought processes.
An empty stomach is ideal for pranayama. Early morning, food consumed during previous day is digested. It is recommended that you should clear your bowels before starting asanas or pranayama.
If you cannot do pranayama in the morning, try to do it in the evening around sunset time.
You can practice pranayama in a well ventilated, clean and uncluttered room with plenty of free space for yoga mat and free movement. There should not be any noises which may distract your mind.
Alternatively, you can practice pranayama outdoors in a garden or a lawn provided weather is neither too cold nor too hot. Do not practice outdoors when strong wind is blowing. Avoid practicing yoga under a fan or an air conditioner as it may disturb the body temperature and cause chills.
Do not eat anything for 3 to 4 hours before doing pranayama.
Follow the principles of yoga diet. Eat balanced vegetarian diet as far as possible which will be easy to digest and keep your abdomen clear.
If you feel thirsty, you can drink water or lime juice at least 30 minutes before starting yoga breathing.
It is necessary for you to feel comfortable and relaxed when you start. Wear loose fitting cotton clothes.
Try to do pranayama at the same time, same place and same pose everyday as regularity increases will power. Even if you practice pranayama for 15 minutes but you must establish a daily routine and follow it strictly. I assure you that after one week of practice you will love to do more pranayama.
For doing pranayama you can sit in padamasana, sidhasana, vajrasana or sukhasana. If you cannot sit comfortably in any of these poses, sit on a chair. While in sitting pose, keep your backbone straight and head in line with it.
You should not be too tired before doing pranayama. Ensure that you get good sleep in the night. In case, you want to do pranayama in the evening after working whole day in office, take rest in shavasana before doing pranayama.
Any time you feel uncomfortable during pranayama practice, stop the exercises. Breathe normally, relax and take rest in shavasana.
A beginner can start practice of Pranayama keeping in mind these guidelines for pranayama. For beginners, rhythmic deep breathing and alom vilom (alternate nostril breathing) are the easiest pranayama for beginners.
As per eight fold path of yoga, you must first practice asanas for few days to condition your body and thereafter start pranayama. During your daily yoga practice, start your yoga sequence with asanas followed by pranayama.
Some people do not practice asanas and just do pranayama only. Pranayama practice alone can improve your concentration, and revitalise your body and mind. These guidelines for pranayama are by no means exhaustive, you can add more based on your experience.