There's quite a few that are good for lower back, the three I do after getting outta bed is laying face down (no compression on back) for around 30 seconds to 1min, then I lay the left part of my face on the floor and alternate for the same amount of time. Next, I rest on my forearms, kind of like a plank but everthing from my waist down is on the floor. After that, I slowly go down to the first position for about 5 seconds and slowly get into the cobra pose; slowly work your way into that and ease out of it when you're done. I also do these and upper shoulder stretches before/after workout/training and before going to bed. Easy light yoga is good for flexibility and mobility as well; I remember when my ish was really bad I was over compensating to one side and it fckin killed me; after doing a bit of different routines my back was a lot less guarded, my hips opened up more and my hammies weren't as tight.
Also, half crunches are good, lay on your back with your knees bent and feet flat on the ground and come up slightly off the ground, hold that for a a second or so and slowly go back. Some people will tell you to go higher up, see how you feel, for me unless I was doing crunches, I never went more than 15-20 degrees when doing a half crunch only as a lower back stretch. Core work is also gonna help out your lower back, just be careful with certain ab exercises and you'll be alright.
Overall, fckin great work so far there man, keep killin it!
