For those of you who do regular stretching - of whatever type:
How often do you stretch?
How long have you been doing it?
How long before you saw positive results?
Do you sometimes see a relapse to tighter muscles?
Used to stretch seriously back when I was doing martial arts - and now never stretch at all
Back then, I stretched about 3 times a week - serious, deep stretching of the hamstrings, groin and hip muscles in order to perform kicks. I also thought stretching was important for exercise in general, so would routinely stretch for football and cycling.
Did the serious stretches for 3-4 years.
I was very inflexible before starting, so made some rapid gains, levelled off some but after about a year I had very good flexibility and suppleness. Overall, but particularly the legs and hips. I considered this positive in the context of the martial art - it made a big difference. In terms of all round well-being it was not a big deal.
I’ve relapsed significantly since then, of course, but never back down to my starting, stiff-as-a-board level. My sport now is cycling, and have found that stretching is pointless for me at the recreational level I ride at. That’s not to say I don’t enjoy a good stretch - I find it quite a fulfilling thing to do, but not so fulfilling that I’ll make time for it after a ride.
Regular stretcher since high school-33 years. Only real break was after my accident, took 8 months before I was able to get on the floor and maneuver well enough to resume.
I was very tight but I have regained most of my former flexibility. Just my left hip/knee are still a problem and that looks to be permanent.
I take a Bikram yoga class twice a week with, of course, includes lots of stretching. I’ve been doing this for three and a half years. I have always had very inflexible muscles and I still do but there has been a dramatic difference since taking up yoga.
I don’t do “regular” stretching, but I do use stretching exercises as needed. The results are immediate in terms of my back suddenly deciding that ok, it will go on being connected to the rest of my body instead of asking for divorce.
I’ve started Pilates two weeks ago and I can already do stuff that was impossible three weeks ago 
A follow up then: Why not every day? Does the muscle need a rest period after stretching, like when you are lifting?
I’ve always stretched every day, never noticed a lack of recovery.
It is possible to stretch too hard and suffer minor tears in the muscle that would require healing time.