A beginner should first connect with the chest and lungs. Developing a capacity to get towards deeper exhalation is the first step in practising any type of Pranayama. Our goal should be to exhale without collapsing the chest. Secondly, we should focus on steady inhalations. This can be done through various combinations of breaths like inhalations in stages, exhalation in stages, deep inhalations with short exhalations, deep inhalations with holding of breath and deep exhalations, etc. Breathing with sensitivity requires development of chest muscles, before advancing in Pranayama.
Developing muscles for asanas is a different concept. The asanas give mobility to the chest muscles, thereby strengthening them. Once these muscles are developed we must take a step further and channelize the mobility with sensitivity and stability for Pranayama.
Pranayama demands the involvement of the gross body and the mind, which is not an easy feat. In asanas, the mind can be dominating or aggressive with lots of fluctuations, and it takes years of practice to make the mind subtle. Usage of props helps to keep the spine straight, as maintaining a steady posture is the key to a good Pranayama.