Do you ever mix the scents? When the hand soaps are on sale, I always pick up some of the vanilla ones, and some of the lemon ones. I find when a particular 'spicy' scent is low in the dispenser, say anything pumpkin, if I add vanilla to it, and combine the smell is quite complimentary. I've found that pumpkin scents, the cookie like scents - gingerbread, buttercream, etc. pair well with vanilla and so do the coffee scents like the I think it's called something latte.
Also I have found if I cut the soap solution with 1/4 or a little more (not quite 1/3) water the 'integrity' of the soap won't be much affected: ie: it won't be less foamy or feel like you need to use more.
I also stock up on the lemon scents (of which there are many) and find they work quite well with the berry scents and some of the flower scents - I just mixed California Poppy with almost half lemon and I really can't even tell a difference.
This is a great way to extend your soaps! I'm always mixing, gently swirling, adding a bit of water to my hand soap dispensers and usually come up with three full bottles, one for each bathroom and one for the kitchen! If you are low on one soap think of what might go good with it to extend it. Sometimes I open them both up and whiff both bottles at once. If they smell good together, this is usually a pretty good indicator that they will work well mixed. This is also very helpful when you find a good solid scent like vanilla on a really good sale. I don't do many of the mixed "theme" scents, like "Paris" or anything like that, I usually stick with the spicy one type scents (gingerbread, pumpkin, vanilla, cinammon, etc.) or the single fruit scents (Apple, etc.)