There are 2 main methods :
- Wake Induced Lucid Dreaming (WILD) : you go to bed and, by different means ( counting, visualizing, etc. ) fall asleep without losing your consciousness.
- Dream Induced Lucid Dreaming (DILD) : you are asleep and dreaming and the principle is to make you aware that you are dreaming. It’s generally based on self-suggestion. The main stream is called Mnemonic Induced Lucid Dreaming (MILD).
You can find some information in the “wings” above the LD4all forum : How/inducing and Starting.
Very good introduction is given in the Wikibook/Lucid_Dreaming :
https://en.wikibooks.org/wiki/Lucid_Dreaming
in the chapter Induction Techniques.
Further information in “The BIG MILD topic” :
https://community.ld4all.com/t/the-big-mild-topic-part-ii/8731
and “The BIG WILD topic” :
https://community.ld4all.com/t/the-big-wild-topic-part-xii/10704
Have good dreams ! 