write out the days you'll be away
lay out possible outfits on the bed...
or hang on a rod...
(click on image for larger view)
Write out each day you will be away, filling in the events and general things you'll be doing; walking around, nice dinner, casual lunch. Either write down possible outfits or pull them out so you can see them, including accessories and undergarments.
Start with events/times you have an idea what you'd like to wear and go from there. The idea is to wear individual pieces more than once, but not the same outfit more than once. Think about pieces that can be worn in multiple ways; a fancy top with a skirt and heels then with casual pants and flats. Also think about simple pieces that won't be obvious you're wearing more than once. For instance the beaded neck top pictured above would be hard to wear twice unless I'm not seeing the same people.
Pick a color scheme to make it easy to mix pieces and accessories seamlessly. Then at the end, toss in an extra sweater and a couple simple tops for just in case....
The pics are from my wardrobe, but this works for those with color and prints as well. If you're outfits aren't layered play around with the accessories to dress an outfit up or down.