If you're going to an event that's going to be outdoors, do yourself a favor and skip the stillettos. But if you absoultely cannot resist... get yourself some heel protectors. They are little plastic pieces which fit over your heels and help prevent them from sinking into the ground or getting caught in nooks and crannies. You can find them in bridal or shoe stores or online through websites like thesolemates.com for around $10 a pair.
If you're hosting an event outdoors, you should advise your guests not to wear heels (but assume that many will do so anyway).You can help them out by providing some ground cover like a tent to keep the ground from getting wet, or you can cover the ground with straw or beach sand (which are also natural materials which will eventually disappear into the ground). You might also want to rent some aisle runners used for outdoor weddings for pathways or between tented areas. To prevent heels from piercing carpets or mats, or just to give them more support, you can try putting down some hard plastic carpet protectors (usually made to go on top of carpet to protect them from rolling office chairs) underneath the carpets. Just make sure to use some double sided carpet tape to prevent slipping. You should be able to find both the tape and the hard plastic at any good hardware store.
Remember that it is always a good idea to have a good, solid floor for dancing. You want your guests to do the twist... not twist an ankle!
(Dance floors can often be rented through the same company where you got your tent).
Happy Planning!