How do you get bonus ingots from pulvs and induction smelters? Gregtech stuff or what? I don't really know a lot about the (thank you, now I know that stuff is from TE, Thermal Expansion right?) TE stuff so sorry if I'm dumb in that regard, my friend introduced me to IC2 stuff when we started our server so that's what I tend to use. I know of most of the TE machines because of DW20's videos though.
Well, for certain ores, the pulverizer has a chance of producing an extra dust. If you pulverize copper, for instance, there's a small chance that it'll also give you one gold dust. Same with tin producing one iron dust. Iron, silver, lead, and I think a few other less-common ores all have bonuses too. As for Induction smelters (NOT the induction furnace, which is from IC2), if you put ore in one slot and sand in the other, it'll give you two ingots just like pulverizing and then smelting in a normal furnace, but it has a small chance to produce something called "rich slag." If you swap out the sand for rich slag in the induction furnace, it'll produce three ingots from whatever ore you put in, instead of just two. The chances of getting bonus dusts or rich slag are pretty low, but every little bit helps.
You can see all of this in-game, by the way. The recipes for Thermal Expansion in NEI show what kinds of bonuses you get, and the chance of getting those bonuses.
But hey, use whatever works for you. IC2 has the advantage of being the easiest to power and having the fastest processing time, but you get two ingots per ore and that's it. Factorization has the highest yield, getting you an average of around 3 ingots per ore, but it's incredibly slow and kind of a pain to set up. Thermal Expansion sits somewhere in the middle, being slower than IC2 but faster than Factorization, and producing a little more than IC2 but not as much as Factorization.
I know there are people on the forums who have figured out all of the complicated math behind IC2, TE, and Factorization ore processing, and could tell you exactly how fast and efficient all the different methods are. I am unfortunately not one of those people.