Tight hamstrings

Misha

Does anyone have any tips on stretching hamstrings? I swear, I have the tightest hamstrings in the world and nothing I do helps. I foam roll, do normal stretches, assisted stretches and I see zero progress. I did yoga for years and still it was pretty bad. I'm starting to weight lift, primarily working on booty and calves, so I really have to get my hamstrings and hips less tight so I don't get hurt. Does anyone have any neat tips or tricks?