1. It may be trite but so true…never go to bed angry. Of all the couples we've talked with and interviewed who have been married 30, 40, and 50 years, this is the most consistent advice they have given us. Take some time when something comes up between the two of you to talk it out.

2. Be generous with sincere compliments and thanks. Sincere compliments and thanks can uplift you and your partner-and can draw you closer. So often a compliment or a word of thanks is followed up by a complaint. If this is your habit, stop doing it.

3. Continue to explore each other. There's always something new you can learn about your loved one, even if you have been together for many years. Don't assume that you know everything about them.

4. Be kind to each other. We're always amazed at how many people say they love one another and they aren't very kind to each other. Being kind means using kind words and being considerate of each other. Even if you have been together a long time, treat each other as you would treat someone of immense importance to you.

5. Even if you are busy or tired, open your heart to your partner. Opening your heart means taking the time to listen and understand your partner. It means telling your partner what's important to you and not making assumptions.

Source: http://ezinearticles.com/?5-Ways-to-Turn-Up-the-Heat-in-Your-Love-Relationship-or-Marriage&id=576740