Probably my favorite trip combination:

1. Take about 20 mg of 2C-I (look it up), either in a capsule or with orange juice.
2. Smoke a bowl or 2 of some Salvia 20x.
3. Just chill and trip your nuts off on the Salvia.
4. As soon as you come down off the Salvia, smoke a bowl or 2 of MJ.
5. About 5 or 6 minutes after your high sets in, the 2C-I will kick in.
7. Trip off the 2C-I and feel happy because of the MJ.

Damn good.

Never tried DXM with weed, though. I'm prolly going to.