Take one suitcase with a good set of wheels and one carry-on tote bag. Keep it as light as you can.

Be sure to put your PASSPORT, DRIVER’S LICENSE, TICKETS, address of your hotel, and itinerary into your handbag.

Important gear:

Hair Dryer (be certain it converts to 220 volts)
Ziploc plastic bags in all sizes (perfect to store things)
Tiny sewing kit
Swiss Army knife with corkscrew
Travel Alarm
Shower cap or hair clip
Wash cloth (in a Ziploc plastic bag)
Hand mirror
Small manicure set, polish, remover, tweezers, scissors
Travel info, maps, lists, etc.

Not necessary but nice:

Inflatable neck pillow (ideal for long flights)
Scented votive candles in holders and matches
Battery operated book light (can be used as a flashlight in case of power outage)
Laptop computer with adapters and plugs
Walkman with external speakers, extra batteries and cassettes or CDs
Paperback books (after reading, I leave them at the hotel for the next English-reading visitor)

Pack in your carry-on bag: 

Address book
Travel diary/notebook
Pens
Business cards
Pocket calculator
Camera and plenty of film OR a digital camera with plenty of memory
Batteries and/or battery chargers that work with 220 volts
Plug adapters for your destination
Eyeglasses, sunglasses, contact lenses and supplies
Cosmetics, cleansers, shampoo, deodorant
Toothbrush, paste and floss
Hair brush, comb, and other hair accessories
Drugs:  prescriptions, vitamins, aspirin, anti-acid, diarrhea remedies, etc.

Pack in your suitcase:

2 pairs of casual pants
1 pair dress pants
2 skirts
1 pair shorts
1 lightweight jacket
folding umbrella
5 sets panties, bras, socks
5 t-shirts
2 sweaters or blouses
1 dress that can go for day or evening
1 bathing suit and pareo (large scarf)
1 sun hat
1 shawl or large scarf
fun jewelry
3 pairs of shoes: walking, dress and sandal (all proven comfortable)
1 large tote bag for day use
1 all-purpose bag for day or evening with a good strap and closure
Travel wallet (big enough for foreign currency, with a place for credit cards and coin section)
Wallet on a string security pouch that hangs around your neck and under your clothes
Large envelope (for financial data, receipts, and miscellaneous papers collected along the way)

Stash these items in a separate place in case your purse is lost or stolen:

Photocopy of passport (makes getting a duplicate easier)
Bank names, phone numbers and account numbers for the credit cards you are carrying
Small amount of cash and a different credit card

Bon voyage!