I love doing Yoga with a timer: you get such objective feedback. This Youtube audio lasts 20 minutes – not too long, I hope you’ll agree, to spend on mindfulness in action – and there’s a chime every 30 seconds. That means you can take around five breaths in every pose (or stay for a minute, or two, and that, my friends, will concentrate the mind, or at least make you aware of how easily it wanders!) and know that you’ve stayed there that long. The minutes fly by, and yet you’re focused. It’s a wonderful experience: highly relaxing. It’s got me back on the mat more than anything else recently (and my zazen practice is also enhanced, though I do switch off all guides to ‘just sit’: that seems appropriate – like taking off training wheels when riding a bike).
I hope this helps you: I’ve got several sequences on this site, and there are thousands of others, just as good, all over the web. So choose a practice, or make one up as you go along, and spend 20 minutes in moving meditation. Greater love hath no person, than to lay down his time to benefit humanity.