As someone who also likes physical paper + fountain pen: how do you carry your fountain pens in a way that they don't leak ink when moving around in a pocket or

As someone who also likes physical paper + fountain pen: how do you carry your fountain pens in a way that they don't leak ink when moving around in a pocket or something similar? (as in, the physical jolt of the pen moving in a pocket causes a little ink to come out of the nib, similar to if you were shaking it)