I get such release from intense pain by lying on the floor and scootching my tush up against the wall, with legs raised up and resting on wall. I stay like that for about 15 minutes, eyes closed, arms relaxed on the floor, and using imagery to envision pain being released from the toes traveling down the legs, into my pelvis/hips/lumbar spine, etc. all the way to my face and scalp. I'm a nice, melted and relaxed marshmallow, feeling great relief. Slowly scootch back away from wall, carefully get myself to a sitting position, from which I carefully get up. Legs feel so much better, although not all pain is gone. I have collapsed vein valves in my legs, which from time to time brings nasty pain from thighs down to feet. I've found that doing this helps with that type of pain. A killer when it strikes up the fibromyalgia pain along with it!
I do self-massage on legs/feet, and have a roller on which I roll each foot to feel awesome release on soles of each foot.
I agree with you about the magnesium supplement, which I take nightly along with extended-release alpha lipoic acid, prescribed cyclobenzeprine (10 mg), and 2 other prescribed meds (cardiac issues). Agree on the hydration also, as well as not being immobile. Stretching exercises in the evening greatly help, but I also engage in some daytime exercise/activity also even if for no more than 10 minutes (depends on how I'm feeling in general). I am kind to myself though, and if my body is indicating that I should lie down, I do so. The key is to find what works best for you, tweak the plan as needed, and allow yourself to rest if needed.
I taught for nearly 25 years, standing the majority of the day. One doctor told me that having done all that standing contributed to the collapsed vein valves and pain issues on the tops of my feet. Had I known back then🤔....oh well, it was my way of being able to navigate the entire classroom and see how my students were doing, and an essential component of my teaching style, so it is what it was😁....