JediMind, for dorsiflextion, there is the "stick" drill I learned at the FMS. The idea of it is to deal with reseating or repatterning of how your talus glides. Google "talus dorsiflextion" and you'll find some things to read or better still, talk to an FMS about it.
I also perform a very simple stretch that helps me. The one I've usually seen recommend is to put the ball of your foot on a step and let your heel drop but I don't find that does what I need. I prefer to stand in front of something roughly waist height, e.g., a kitchen counter or my front porch railing. I stand with the heel/ankle I'm trying to stretch a little bit behind me and try to put my weight back on that heel - the further back you place that foot, the more of a challenge it is to get the heel on the ground. For me, the sweet spot is where you can already get the heel on the ground but only just, and you then try to relax your weight into that heel, getting a little bit more stretch. A few reps, perhaps moving the foot slightly further back as your range of motion increases. I feel it in the bottom of my calf and it makes my pistols better.
Hope that helps.
-S-