Unfinished and expired perfume - what do you do?

Say, your $100 dollars perfume has expired but you merely used them for like, less than 10 times?

We all know there's expiry date for perfumes and the scent turns funny afterwhich. But seriously, aside from discarding them, are there any better alternatives?

Here's a few things I normally do with my unwanted perfumes:

1) Potpourri - spray those CK's scent onto it to extend it's fragrance.

2) Room spray - sick of all those typical room spray? "Upgrade" your room's scent with your Chanel no. 5 instead.

3) Drawer fragrance - moth ball stinks, despite it's almost a necessity to repel cockroaches and bugs but it too stench our belongings, so spray some Kenzo into the drawer to diminish the moth's ball's smell a little.

4) Shoe cabinet - you know it stinks. C'mon. Any smell is better than those from the shoe cabinet, let alone the high class Issey Miyaki.

5) For the bimbo's - spray your Lancome Miracle on daily belongings like stationaries, notepads, notebooks, pencil case etc.

For the hong kong feet, maybe can try your Hugo on the socks too? Be creative!