I never really even touched forging. At the time I made the weapons I usually didn't have the parts needed to add them, and then later when I did I would forget.
The exception is I purposefully forged a dagger with 1 forge each of stun, petrify, paralyze, sleep, and something else I think which I then gave to my Arcanist who seems to land at least 1 of those a lot of the time (I would say 50% chance or so to get at least one).
Not crazy effective but it amuses me to have my arcanist stab for no damage and then the enemy dies from petrification.