Biting, hard and soft.
Soft: I tend to bite my wife softly, even in non-sexual ways, like taking her hand and lightly chewing on it, or her arm. I don't know why but it makes us feel close. Maybe it's kind of a nervous habit.
Harder: We tend to bite each other kind of harder during sex. At least I have to assume it's harder because we tend to leave marks. It doesn't really hurt at all, though, because it's usually in the heat of the moment. A lot of times I don't even realize it until afterwards.
Scratching. We do this very similar to the biting. We will lightly run our nails over each other, which can be relaxing or stimulating depending on the context. During sex it's usually rougher, but we don't always notice it in the heat of the moment either.
I don't know if lube is covered by toys, but I figured I'd chime in with that. We like regular lube, flavored warming lube, warming massage oil and lube in one, flavored massage oils, etc... Although we are not super into erotic eating, we still incorporate licking and flavors into our love life. It feels less messy for some reason.
Also, bed cuffs, so both arms and legs can be restrained. Hand cuffs are also good, just good in every position due to the metal digging into your body. And door cuffs. Pretty much restraint in general. It is wonderful for teasing or to relinquish total control to your partner.
And of course, I have to mention blindfolds since I mentioned restraints. Blindfold + Bed cuffs = a good night.
Feather tickler. If you have the patience to be this gentle, it can be an amazing experience. It stimulates a lot of parts of your body you wouldn't normally consider erotic necessarily.