It is very important to consider your posture when you sing. You use your voice as an instruments, and like all instruments, you should know how to hold them correctly. When we sing, we use our heads, throats, chest and abdomen to create our sound, so it is important that we maintain a posture that benefits these areas.
It is difficult to draw in to the bottom of your lungs if you are sitting down, so stand up.
Stand tall, with your shoulders back and let your arms dangle loosely by your side.
Keep your head up so that it opens your airway
Feel yourself being pulled upwards from your navel to the top of your head, so that you create more space for air in your lungs
Try standing with your knees unlocked and with one foot slightly in front of the other, about shoulder width apart
Try to keep your abdomen muscles tight
Relax but don’t slouch!