Poison, missiles, 1.10

[Ruvanal]

There's a fairly common myth that certain combinations of high damage long duration poison sources and low damage short duration sources are a way of maximising your effectiveness

Maximizing in what way?

With poison damage if you want to increase damage per second you need every source you can get

Fairly accurate. But you may want to to go for some of the items that have the highest rates as it may take 2 or 3 items with a medium rate to equal one with a highe rate (saving you inventory space or equipment slots).

If you want to increase damage per shot then with melee weapons, and in 1.10 missile weapons too, the min/maxing I described is effective

??
If I am just using a character that is using a fast form of attack, I just use a little poison to help stop the monster from regenerating their life since I will usually be hitting them again for more damage well before the duration runs out. Even if I am using a slower weapon, it is typically not worth it to me to be using any of the low rate poison damage items, better to use those slots or the space for other better equipment. If you are not going to let the poison run through its entire duration, then the only thing you should worry about to increase your poison damage is to use the highest rate items that you can.

If you do intend to let the poison run its entire duration, then you would want to arrange your items to try to maximize the duration in most cases. Typically by having the poison run for a longer duration you will do more damage than a slightly higher rate and somewhat shorter duration.

Example:
Tal rune will do ~15.039 damage/second for 5 seconds
Perfect Emerald will do ~14.355 damage/second for 7 seconds

While the Tal rune has a higher rate of damage, if you extend the damage out to when they have both finished the perfect emrerald will have done more (Tal rune= 75 damage and PEmerald ~100 damage). You would have needed to reapply the damage from the Tal again for it to do more damage over the 6th and 7th seconds; taking away from potentionaly apply poison to other targets.