Tickling brings forth some really nice expressions, and mixes in some bondage and torture in a lot of cases. Helplessness is what makes this as appealing as it does. It's not to the point for me of being a fetish in and of itself, but it's definitely something that can be arousing when combined with simple nudity or other sexual situations.
As for combining it with sneezing, feathers are probably my favorite tool due to the control behind it, and well, I guess my like for feathers carries into both. :3