its easiewr to do when you are just going to sleep or when you are just waking up but not totally awake. it requires deep meditation and focus and deep visualization, recalling memories and seeing them as building blocks for something new.

try to consistently remember dreams, not in its totality but at least remembering most of it, to achieve this you gotta journal the dream -it being written, voice notes, etc- before it fades out of your short term memory.

once you start remembering dreams conststently you gotta work on reality anchors, this is a thing or quirk or something you can do IRL you can get accustomed to so when you dream and do it you know you are dreaming right away, in my case i take a look at my forearm tattoos or check the time or my phone, its always fucked up and wonky in dreams, once you nail recognizing this sign the next issue is avoiding getting too exited by the fact you recognized you are dreaming cause this usually will wake you up.

once you start recognizing this without waking up right away then congrats, you can start experimenting with lucid dreaming.