You should always try new things, like things you guys haven't tried yet, that always sparks things up, and who knows, you guys could like it. New toys might even help, but always ask your partner first. Whipped cream is pretty fun as well. =]
Try things you've never tried before. IF you want even you can buy little things to use in bed. One time my boyfriend bought eatable powder and it was really fun and it tasted good. Or try your fantasy (ask her first) and ask her what hers is.