Lucid dreams sometimes occur spontaneously without the dreamer inducing them or intending to have them in any way, especially in youth. However, spontaneous lucid dreams are rare and depending on solely on these is often not satisfactory for a lucid dreamer. Thus, induction techniques have to be used to induce lucid dreams.
There are many induction techniques, often going by an acronym such as WILD or DILD. Most induction techniques involve training the brain (e.g. using mnemonics) towards lucid dreaming soon before or during the transition from wakefulness to sleep. The induction technique favoured by the dreamer varies and it is quite often found that one technique for one dreamer can be more sucessful than others.
There is always a chance of failure with induction techniques, and the frequency and quality of dreams induced in such ways are not guaranteed, but it is generally recognised that more rigorous techniques such as wake initiated lucid dream technique often trigger more vivid lucid dreams than the more beginner-friendly counterparts such as mnemonic induction of lucid dreams.