1. REMEMBER your manners and treat everyone you meet with respect. Take time to truly see and hear those who are often overlooked – from the homeless man who shelters in a doorway to the tired waiter bringing you your lunch. As a former waitress myself, I know firsthand how a simple smile from someone can improve your day, and how a single harsh word can destroy it. Being courteous and thoughtful costs you nothing, and can sometimes pay you dividends in unexpected ways.
2. Keep your focus on the positive. As a child I loved the book Pollyanna by Eleanor H Porter, about the little girl whose father taught her how to play the "glad game", which involved looking for the good in every situation. I think of that whenever things get difficult in my own life. After the loss of my sister – my darkest time – I tried to think of the beauty she'd brought to this world and the lives she had touched and the love she had left behind. It's not always easy but I've learned that if I just look for the good I can usually find it.
3. Be flexible. Motherhood has taught me that the best laid schemes indeed "gang aft agley", as Burns declared. I can have my day carefully planned, but if someone wakes up with a cough or a sniffle then everything changes. Thinking quickly and adapting without grumbling are essential skills to learn, in my opinion.
4. Don't say anything about a person that you wouldn't tell them to their face. I grew up in a very small town where nearly everyone knew each other and odds were that whatever you said about a person would make it back to them by nightfall – something incomers learned, to their frequent embarrassment.
5. Erle Stanley Gardner, who wrote the Perry Mason books, said that if you're scared of something, then you should wade right out and meet it. I've used this advice and found it works – if I just cross that room of strangers and say, "Hi", to someone new, or tackle something in my writing that I'm not sure I can manage, good things almost always come of it.
6. Pick your battles and be careful how much you complain. Not everything is worth the effort, and as my dad told me once, the squeaky wheel will sometimes get the grease, but occasionally it just gets replaced.
7. Breathe. Things move so quickly these days we forget that they don't need to. I vividly recall the day when my daughter, then two years old, wanted to do something as we were rushing to get out the door, and I told her, "I haven't got time". She just stood there a moment and looked at me, thinking. And then she pretended to reach in her pocket and holding her empty hand out, with her solemn brown eyes, told me, "Here, Mommy. Take some of mine". We could all use a handful of time, now and then, to remind us what's truly important.
• Sophia's Secret by Susanna Kearsley is published by Allison & Busby, priced 7.99. It was shortlisted for the Romantic Novel of the Year 2009.