Sure, but it might not be the answer you want to hear.

To cut them to the same length, I have a piece of Styrofoam with a cutout (length 0.5"). The heatshrink is then pressed into the cutout, and scissors do their job.

Just make sure the sleeve is exactly the same distance from the end of the pin, then secure it in place with self-closing tweezers or fingers. Put the heatshrink over the sleeve and pin. Tilt the wire slightly downwards, so that the end of the heatshrink rests before the two fins on the pin. Then shrink away.

If the distance from the end of the exposed heatshrink to the end of the sleeve is too long, then take an exacto knife and cut away a small ring. If the HS is too short, cut it off and start again.