Five years after my atheist bus campaign went global, I'm launching a very different kind of campaign. One night this year, as my two-year-old daughter was curled up next to me, I looked at her and thought: "I don't mind what you do when you grow up, or what you look like, or who you choose to love. I don't mind if you become a bin lady, or sext your boyfriends during assembly, or get a tattoo of Michael Gove. I only hope I can teach you to be kind."

I knew I had changed when I realised that I didn't mind whether Lily grew up to believe in God or not. Instead, I worried about the world she was growing up in. I wanted it to be a kinder place – but what did that mean in practice?

If I didn't know what kindness was, I couldn't contribute to this vision of the world, and, if I wasn't kind, what hope did my daughter have of contributing, either?

It is hard to define kindness. I see it as acting for the benefit of humanity, animals or the environment. It doesn't invalidate the act if people know about it, nor if the giver feels good as a result – as this Harvard study shows, this effect is a happy by-product of giving. Unfortunately, the coalition government's cuts are the exact opposite of kindness. I wonder if the uncaring example it has set is partly why research published today suggests that nine out of 10 Britons rarely perform a simple act of kindness.

As an atheist without a rule book on how to act, I looked to my friends for inspiration. There was Graham, who had given blood 50 times and had been vegan for 12 years; Nick, who had signed up without remuneration to an NHS medical trial; and another Nick, a charity worker and former VSO volunteer, who had organised a sponsored cycling trip in aid of disabled children in Tanzania. I was surrounded by people doing good things, and I'd barely been aware of it.

I resolved to become a better person. I spent six months training and qualifying as a massage therapist, then gave massages for 40% of the going rate to charity workers, nurses, students, the unemployed and people on low incomes. I went to donate blood for the first time, signed the organ donor register and became vegan. I recycled as though my life depended on it, switched my electricity to Good Energy, and signed up with Age UK to volunteer to visit an elderly person for two hours a week. I also decided to sell 50% of my possessions in eBay charity auctions (which started last night), aiming to raise more than £3,000 for Médecins Sans Frontières. And, unexpectedly, I found that every new thing I did made me happier.

It is impossible to talk about your own acts of kindness without looking as though you're after praise and yet, if you don't, you can't reasonably encourage others to give. As a single mum on a low income, I'm unable to give much to charity or spend much on ethical companies – so I've decided to write and campaign about philanthropy instead, in the hope that it will encourage others to do so. I asked my altruistic friends for help, and together we created a campaign advert and wrote an ebook, Give: How to Be Happy. The campaign, as explained in the book, is called Give Just One Thing, and the idea is to encourage everyone to make a commitment to one of the 10 actions outlined in each chapter, from giving blood to voting in every election.

I will always be an atheist. However, I think that encouraging people to change their actions is more essential than trying to change their beliefs. If everyone in the world became an atheist, it wouldn't solve all the world's problems; if everyone became kind and good, it would.