Dear Sophie,
Hopefully, the psychometric testing will ensure that the partners who are suggested to you are suitable. However, internet dating is also a numbers game, and the more people you meet, the more likely you are to meet someone you really like.
My advice is to try and make the 'about me' section as original, interesting and entertaining as you can while remaining honest. Try to avoid writing the things that appear on the website most often -liking walks by the sea or hating people who are arrogant and rude. These things are true for most of us and therefore lose their significance as a way of working out whether someone is likely to click with you.
It's also a good idea to expand your age search criteria significantly (I would suggest a 20 year range) and to be as active as possible, so send out 10-15 contact requests to begin with and then another 5-6 every week.
Best Wishes, Paula