1. Love yourself
Unless you love yourself, it's hard for you to believe that anyone else will.
Self-esteem is important for a healthy relationship. When you truly like yourself, in spite of any failings and weaknesses you may have, you'll feel confident. And when you feel confident and secure within yourself, you can enjoy being with your partner for the joy they bring to your life, not because you feel you need them to survive. For tips on building confidence see the Improving confidence site.
If you've had bad experiences in the past, it's worth working through these issues with a trusted friend or counsellor. It can be tempting to lean on your partner and rely on them for reassurance, but the stronger you are as an individual, the stronger and more equal your relationship will be.

2. Like your partner
Healthy relationships happen between two people who really like each other. It may be more romantic to talk about love, but it's important to remember that love is an emotion that comes and goes.

If you genuinely like each other, enjoy being together, agree with how each other thinks and behaves, and share the same dreams in life, then loving feelings will never be too far away.

It's important to tell your partner you like them, too. Warm words of encouragement and support build trust and respect. Add the odd compliment as well and you'll be helping to boost their self-esteem.

3. Make quality time
The importance of things can be measured by the amount of time we're willing to give them. When a couple first gets together, they instinctively prioritise their relationship. But as time goes by and life gets busier with work and children, time together often slips down the list of priorities.

If you don't spend regular quality time together, chances are you'll drift apart. Making such time for each other may mean sacrificing other activities, but remember it's an investment in your future happiness.

4. Communicate
Good communication is essential for a healthy relationship. It's the only way you can tell your partner who you are, what you want and why you behave the way you do. Talking is the way we let each other into our private worlds.

Communicating better is about learning to say openly and honestly exactly what you think and feel. It also means listening to your partner without judgement. For more see Talk and listen.

5. Argue well
It's important to accept that arguments are a normal part of a relationship. We're all unique and so we're bound to have our differences.

Couples who argue well don't have to worry about not always agreeing. A good argument is an opportunity to share your feelings and strengthen your bond by reaching a decision you're both happy with. It can be an experience that leaves you both feeling more confident about your relationship and brings you closer together.

6. Touch every day
Touching is a vital human need. Studies have shown that without touching, many animals - including humans - will die in childhood. Being caressed also lowers blood pressure and releases natural opiates in the brain, as well as the chemical oxytocin, which is essential for human pair-bonding. For more, see Sensual touching.

Touch has the power to comfort and support, to protect and encourage, to relax and, of course, to arouse. Every couple knows their sex life may have dry periods, but our need for physical affection never changes.

7. Accept change
People change over the years and it's these changes that can keep a relationship alive. Life changes too - and not always in ways that we want.

Change can provide opportunities for growth and intimacy, but it can also be painful. It may mean adjusting to a new way of thinking or a new way of life. It may also mean letting go of things that have been familiar and safe.

In successful relationships, couples learn to adapt and change together. They accept that change is an inevitable part of human life and support each other, for better for worse.

Keeping all seven principles going isn't easy, but the more you can manage on a regular basis, the stronger your relationships will be.