It's nice to be alone, the two of you, kissing and hugging, but do not forget about your friends. You, the boy go with boys to have a beer, or to watch a football match, she, the girl needs to be with girls and go shopping or visit a beauty parlor.
It's obvious you want her to be with you, but be careful. Have your own ''tasks''. You need private space. It does not mean you meet only twice a week but you both have your own circle of friends and you need to be with them.
2. You let her do the planning
Not only that you end up like a puppy but she will get angry with you telling that you lack initiative. Don't let her alone in planning trips or visits, you are a couple, you need to do it together.
3. You leave out unknown things from your past
Maybe your girlfriend needs to know you were engaged, nearly married, you have a child from another relationship, you are adopted, etc. There are things that should not be kept in the dark. Even if there are issues you are not proud of, the truth will come out. It's better for you to tell the truth, than let others tell her things she did not know about you.
4. You avoid facing her
Whenever you think a fight will appear, you reconsider. This is not the idea; you need to say what you want. Be attentive to your tone of voice; reject shouting, because you can end up sleeping at a neighbor or on the sofa. More than that, communication is very important - try to explain to her what is it that makes you unhappy and so you compromise.
5. You forget all her mistakes
Has she lost the necklace from your grandmother? Did you not wear your favorite shirt because she didn't like it? Does she cancel meetings on your behalf? This is serious. If she sees you forgive her, irrespective of what she does, she will go on. You need to build-up couple personality, to understand what is right and what is wrong so you know what is good or not to do about your behavior.