I'm seconding the spin-in-place suggestion.
The first time I realized I went lucid I was slowly starting to wake up and everything was fading to black. I imagined myself walking / spinning in place and I snapped right back into the dream. Everything suddenly became very detailed and vivid, it was a really surreal experience.
I've been lucid two more times since then but I'm a pretty "weak" dreamer. Like I'd try to manipulate reality and I'd have very little influence on my surroundings. I would try to change the color of things (like the sky) / conjure things / try to start flying but the results were so-so. Also, does anybody have judgement impairment when they're lucid? As in you realize you're dreaming and you have control… but some of the logic you have when you're awake just isn't there.
Also every single time I've gone lucid was right after I walked through a doorway. Like I'd exit a room and enter a hallway and then I would suddenly realize I was lucid, very abruptly and unprovoked. I'm not really sure what that means but I'm going to keep using that as a reality check I guess. Every time I go through a door irl I'll just do the "am I dreaming?" check and hope it sticks. I used to wear a ring and I would switch it back and forth between my left and right hands as a way to help me remember to do dream checks, but I never noticed the ring in my dreams.
Though the times I did those checks regularly were the three times I went lucid so I guess its effects can be really arbitrary? Just thinking about it a lot was a lot more helpful to me than light switches and noticing clocks I guess… but that's just me.