"Like the leaves on the trees they're ubiquitous yet rare. Every one is different, different in shape or marked in a different way. But unlike leaves they have weight and heft in the hand. They're solid and heavy and (though this, of course, is an illusion) reassuringly permanent. They're cool to the touch but comforting to hold. They're free but precious, too: a favourite pebble can become a talisman, a minor household god, a Becketian worry-bead, even a smug little social mark. They're as refined as the most delicate sculpture, yet they're also tough as nails."
I have found it helpful to do the stretching exercises my physical therapist recommends. Do some core strengthening exercises, such as the ones highlighted at The Mayo Clinic. By keeping your core strong, your back won't put itself in a position to cause that sciatica pain you are having.