Does anyone have any tips for travelling lighter?

I'm goin on holiday this summer and need some ideas on how I can pack so that I only have to take one suitcase... thanks :)

How long will you be gone? instead of folding your clothes roll them. Only pack one outift for each day you'll be gone (but only up to a week's worth of clothes). don't take too many clothes with. If you need to you can always go to the laundry matt (sp?). Only bring 2 pair of shoes no more than that. Don't bring the full size bottles of bathroom products. Go to walmart and buy the empty travel size containers and put your products in them or wait till you get to your destination and buy small bottles of bathroom products there and then toss them out when you leave...this way you don't have to bring yours and it saves space in your bag. There are so many ways you can save space in packing. Put things in ziplocs so your products don't leak out into your clothes.