I'm trying jigging/casting a spoon and noticed that it twisted my line.  I was using a 3/4 oz spoon with a #12 snap swivel on 12# test with a baitcaster.  I'm wondering if a bigger swivel is needed.  Or even a ball bearing swivel?

Any thoughts would be greatly appreciated.

Snap swivels suck.  use a split ring, and a barrel swivel, like this:

I really like the war eagle spoons because they already have a swivel on them.  On my other spoons I will add a swivel like JFranco.  I do however tie my line to a fast lock snap as I tend to mix it up between spoons and ice jigs when I am spooning.

I use a swivel to attach my leader, then a duo lock on the spoon, makes lure changes easier for me and seems to work well.

In saltwater I still use swivel and leader(except for mackerel) but tie my spoon using a loop knot, lure changes are made less frequently in the brine and not unusual to use same lure for long period of time.  I use spoons probably about 75% of all my fishing.