This is less of a techinque and more of a regime but stick with me:
1. Get your heart rate up by jogging/walking or some such activity for at least 15 mins. As i'm sure you know this is good for releasing all those relaxing brain juices.I find the best thing to do is a circular route so that you end up back home for step 2....
2. Have a long warm shower/bath and concentrate on making your body nice and fresh and you could use something on your skin to make it feel super sexy, chaps can use unscented moisturisers. Rubbing cream into your skin is itself relaxing and gently massaging all the bits you can reach helps you relax, even better get someone else to help you relax all over!
3. Finally lie flat on your back, on floor or supportive mattress, close your eyes and focus on relaxing all parts of your body, starting with your
feet, and working your way all the way up to your neck. This takes concentration and takes your mind off the day's stresses. You might find you need to stretch before relaxing, i've no idea why this helps but it helps me. I use this final technique to fall asleep if im stressed or restless and it really works, if you're still not 100% relaxed just repeat the process, feet to neck breathing deeply and slowly. and for your purposes try not to fall asleep!
hope this helps,