I'm looking to improve my flexibility, because it's truly awful at the moment (forget touching my toes, I can barely get my hands past my knees 
) Ideally I'd like a short routine that lasts about 10 minutes or so and can easily be done a couple of times a day. So far I'm incorporating:
- touching my toes (or what passes for it with my body!)
- box/straddle splits (ditto)
- side lunges
- cobra stretch
- a variant of the cat stretch that involves lowering the chest as far as possible (I've also heard it called 'cat stretch', but it's not what comes up when I google search it)
I'm trying to hold each of these for 3x20 seconds with a short break in between, in a position where it's uncomfortable but obviously not forcing it til it's painful or anything like that. Is that enough to make any difference, and are there any other stretches that would be good to include? Or is there a better way to do it in general? I'm in my early 20s if that makes a difference.