Well I've only had my bocks for 1 day, and I'm already running in them. Here's what I found works for me:
1. Jump and land on your least dominant foot (in my case, the left). This should make you "hop" slightly. Land on your dominant foot and push off, but this time you're going to swing your left foot out in front of you and lean forward.
2. Once you've landed on your other foot, put all your weight onto it and swing out the right foot. Use your HEEL, not the frontal ball of your foot (toe area). The more weight you put into a single leg, the bigger the jump will be and the long the strides.
Now, I found that to stop running I generally start "tapping" the bocks quickly in succession while leaning slightly backwards to counteract the forward movement.
Always make sure to use a flat surface or slightly downward tilted hill (no more than 5, 10 degrees?). Don't try uphill until you get used to averything else, you'll trip because your legs aren't used to the heavy weight and thus they drag.
