It's possible that you may have a love/hate relationship with props! However, there's no doubt that props can be very useful in advancing your practice. Props are especially beneficial for beginners who are trying to achieve correct alignment. This class
Back to Yoga Basics: How to Use Yoga Props + a Free Yoga Prop Guide
Yoga Fitness Flat Belly - Flexibility Resistance Band Yoga Belt with 8 Loops, Yoga Strap Stretch Strap Exercise Strap (Blue) - There are many alternatives to get a flat stomach and among them are various yoga poses.
This technique is very useful and effective. I have used it many times before. -- How to use a long yoga strap to help move your shoulders back and down - reducing stiff shoulders, sore necks and upper back pain. (Upper Back Pain)