Ask a Warrior Thread.

People who are most concerned about optimizing their spear would say to forge with an adv str, diamond, black crystal, and a stimulator to ensure the highest possible attack.

I myself just used str, dex, and diamond with no stim and got a 118 atk clean, but that was mostly a fluke.

If you want to scroll, it's probably recommended to use the Legendary Spirit skill so you can sell it off if the scrolling goes badly. If you're feeling really lucky and/or rich you can 30% the first slot of a few spears until one works and either straight 60, 50, or white scroll it to perfection. I, and I expect most people, just straight 60'd from the beginning. I managed to get 4 to work, and 5 more atk from levels made me the proud owner of a 131 atk spear Then again, I had a friend who made pretty good clean dagger, but only got 1 60 to work and no atk from levels so far, so it's pretty much luck...