They're easiest to trigger during mornings when you wake up, or during naps. The reason for this is due to dreams occuring during REM sleep. Lucid dreams trigger most commonly when you're going towards REM sleep. The most common way is through mindfulness, what you have to do is to let your body sleep, but to keep your mind awake. This is why it's easier to lucid dream while waking up because your mind won't rush to deep sleep and it won't get to deep sleep as fast. Most of your opportunities will come from stumbling across you already being in that zone of slightly lucid. When this happens, you will feel intense vibrations through your body kinda like you're being electrocuted, and it'll get intense with every breath. It will feel scary and for the first few times, it will throw you off, but you get used to it overtime and after experiencing it many times. This occurs because your brain is still awake, but it's losing touch with your body since it's falling asleep and your brain can't detect where your body is so it just randomly pings in the general area of your body. Eventually, everything will quiet down and you will feel like you're in your room, looking at the ceiling (if that's what you were facing), but you're also aware that your real eyes are closed. Congrats! You're in a lucid dream.