I was the girl who was always up for a drink. The one who made other people feel better about their own drinking, because I would always join them, and generally outdrink them.

From family gatherings to bonding with colleagues, partners or 'mum friends,' every one of my relationships seemed to be built on booze. And drinking was how I relaxed: a glass of wine with dinner after a tough day at work, or a cold G&T after battling the kids into bed.

When I hit my thirties and began to notice the toll that excessive alcohol was taking on my body, skin, mood and energy levels, I decided it was time to cut down. That's when I realised doing so is easier said than done.

Moderation sounds simple, but it's really more complicated than abstinence, largely because, after one or two drinks, your willpower and decision-making skills go out the window. Lasting change is particularly challenging since moderation requires constant awareness of your behaviour and decisions.

One of the most common reasons for drinking too much is doing so without really thinking about it. Accepting a glass of wine because everyone else is having one, or pouring yourself a drink at home every night. Mindlessly doing something because you've always done it is a tough habit to break.

But it's worth breaking. Moderating your drinking will improve your mood, your digestion, your skin and your body, as well as sharpening your brain. Everything from your bank balance to your sex life will be better. It also automatically moderates other bad habits, like social smoking, hungover binge eating and mainlining coffee to get through the day after a night of fitful drunk sleep. We live in tense times, and people see alcohol as a stress-buster but, actually, the link between excessive alcohol and anxiety is inescapable.

In an effort to teach myself how to drink less, I wrote a book about it, Mindful Drinking: How Cutting Down Can Change Your Life. I interviewed psychologists, mindfulness gurus, behaviour change experts and successful moderate drinkers to create a programme that has changed my life.

It's all about awareness, and preparation. Think very carefully about what, where, when and how much you intend to drink in the future. Aiming simply to 'drink less' is way too broad a goal. You need to be very specific. I go by the Rule of Three. This means I only allow myself to drink on three days every week and, on the days I do drink, I have no more than three drinks. Then there are many ways to help you stick to it:

• When it comes to social occasions, plan exactly what you're going to drink, and how much, in advance. Have an excuse in mind if a well-meaning friend tries to pressure you into drinking more than you intended.
• Come up with a list of alternative stress relievers that you can turn to if you're tempted to reach for the bottle. It could be anything from having a bath or going for a run, to dancing around the kitchen to hopelessly uncool music.
• Find a signature soft drink. Once you have an alcohol-free drink that you enjoy and feel comfortable ordering, you will never again panic, flail around and agree to a wine when someone else is getting a round in.
• Practise sober socialising. Meet friends for brunch at the weekend, or a coffee in the afternoon. The more you arrange sober social occasions, the less weird it will feel.
• Monitor your drinking DrinkAware's Track and Calculate Units app is really good . Since studies have shown that monitoring habits helps improve them.
• Reframe slip-ups in a positive way: i.e. falling off the wagon helps you identify a trigger that you can now anticipate in the future.