thank you
It's been a pleasure working with you, and I'd love to do it again sometime. As my way of saying thanks, I'd like to offer you £10 off your next invoice when we work together. 
All you have to do is fill out the small review below and tag me in a post on Facebook or Instagram - simples!
Thanks again, you're the best! You can now use this code when I next invoice you, to get £10 off:

Your feedback means everyone wins:
1. My future clients will be happy because I improve when I receive feedback
2. If you leave a positive review, you will be happy because you said something nice*
3. I'm happy because good reviews will help me to get more work!
*It's scientifically proven that being kind to others releases two important feel-good chemicals: Oxytocin and Serotonin, so you'll be feeling all warm and fuzzy on the inside!