Hey my fellow lucid dreamers ive got a question that has been buggin me for quite some time and i was wondering if you could guide me in the right direction here goes

do you have to enter SP in order to become lucid or can you become lucid in just a ND ? If you can become lucid in just a ND how would i go about tellin myself that i am infact dreaming and what methods would i have to use ? ive heard of RC is there any others ?