I recently came across something called the "Power Thank You", courtesy of Mark Goulston (American Psychiatrist and Consultant to Major Organisations). You will find this short quotation from Goulston’s book Just Listen, all over the internet, but here it is:

"if you’re deeply grateful to someone who’s done an exceptional favor for you, you need to express that emotion by going beyond the plain words ‘thank you’ and instead offer a Power Thank You. When you do this, your words will generate strong feelings of gratitude, respect, and affinity in the other person”. 

This is as valid outside the workplace as it is in, and today, back from our travels in Thailand, I would like to say a power thank you to someone who made a difference in my daughter’s life, and therefore mine.