I think what really helped me with my mindfulness practice was that I was lying down instead of sitting like I normally do. When I sit while meditating/practicing mindfulness, I am more likely to fidget, or become uncomfortable or distracted, as opposed to lying down. I found myself more calm, and therefore able to complete the practice more easily.
I find that mindfulness helps my brain become both more calm and focused, and it generally leaves me in a better mood. This really helps me stay on track and not give up while doing work. I am able to get things done without getting distracted, and also having a good mindset.