This topic interests me, I have used indirect techniques to increase the rate at which I get into a lucid dream state, drugs are not necessary with the correct schedule. However like others here have noted sleep quality is reduced and REM does not seem to have the same restorative effect if you spend it lucid dreaming.

I was actually first taught how to do this by my Chinese martial arts teacher, he recommended I spend any time I had in lucid dreams shadowboxing and sparing with opponents and in situations (often against weapons) I fear the most. It has actually increased my ability to think objectively during stressful situations. Especially because when you get too excited in a dream it usually collapses (look up deepening techniques if this is a problem for you).

One way I have heard people use this technique outside of martial arts is practicing public speaking in the dream state to increase confidence and create a realistic practice environment. Of course the possibilities are wide, however I find it very difficult to do things I have not experienced in real life, for example I can jump really high like I would if I was on a trampoline but I can not fly around like superman.

This is the Guidebook that taught me the fundamental techniques: https://www.obe4u.com/files/the_phase/the_phase.html

Happy Dreaming all, it's the weekend give it a try!