Do what you are doing - that means approach it like yoga - rather than union, think of linking. Linking yourself completely to the action or moment at hand. Not in projection or obsession on the outcome, but just in an engaged and present way. That also means leaving history in the past; don't approach it with all of the former experiences or occurrences, both good and bad at the forefront of your mind, for in doing so, you are repeating history, not crafting the present.
Let me make it a little more tangible - right now, is your singular intent reading this? Really, I'm flattered, but are you eating or drinking something? Listening to music? Have multiple windows open and actively panning for excitement, or simply just hanging out somewhere in public but checking out some blogs and then some people, then whatever?
The question is, is that how your practice goes? Are you elsewhere, making big or small plans? Checking out ideas in your head, remembering the good times, thinking about what you'll eat later? It's natural, it's the practice, to understand that tendency to disassociate and pull away into reflection, distraction, projection - anything but the experience or sensation at hand.
Can you use the breath, as the yuj - the link - the one thing that binds you to what you are doing? Can you experiment with simply trying to give your fullness to one thing alone? In the asana practice, the linking of breath and body and engagement; perhaps in your life for a selected experiment. A time without multitasking, without rampant sensory input, perhaps driving while not listening to music and making a call while texting! Perhaps, just to be present to your loved one, to only listen to a song, to just simply read a book. To just do what you are doing while you are doing it.
Perhaps that can be working experiment for you as you transcend your practice from the safety of the laboratory and into the screaming mess we call life. Where do you most easily get distracted? What are your multitasks that are productive, but which are the ones that are distracting... when is the last time that the only thing you did was listen, or read, or think?
Give it a try, let me know what it feels like to feel what you're doing and do what you're feeling!
Give thanks and praise.