I did some combining with something I wanted (lower blood pressure :-) and did some trials of before and after very short (10 minutes) of trying to meditate/just rest my mind; and I also did a self-touch of my knee test (blood pressure went down!) where I just gripped my knee lightly and concentrated on the feeling of being "held"/cared about. Sometimes when I'm taking my blood pressure (my monitor takes 3 readings in a row and averages them, 30 seconds apart from each other) I'll notice my shoulders are hunched and work at relaxing and usually have to do that over and over again, just as you say! But concentrating on a short bout for a specific purpose instead of looking forward to when I can "meditate" helps me.

Practicing "mindfulness" instead of meditation has helped me later do medication, too.

http://www.psychologytoday.com/basics/mindfulness