Hi LoveFairy,
First of all, you should have a look at the “What”," First" and “How” buttons of the LD4all main page. You can find there a lot of good tips.
Then you have to increase your dream recall.
Once it is good enough, you have to choose a technique. There is a sticky thread about it. You can find it in this very section:How to Choose Your Technique.
And you can also read the LD4ALL Forum Guidelines - Read this First! topic, especially the “Before Posting a new topic” chapter. 