>PACK LIGHT / CARRY-ON ONLY
Pack light Pack light Pack light
Reasons for this:  You'll walk more with your luggage than you ever expect—even on a tour.  Also, carry-on allows flight flexibility—you can standby for the earlier flight that cuts short that long layover (not allowed with checked bags).  Plus, avoiding checked baggage charges.  Bonus:  A liberating vacation from our daily burden of possessions—distill to essentials!    

So!  One carry-on size suitcase and one daypack per person.  Buy the right suitcase (see Equipment).  Lay out everything you think you need and take away a third.  Strive for carry-on only.  Don’t make excuses—there are a few situations where this is not possible, but most of the time it is.

The System:  Suitcase-shoes, clothes.  Daypack-optics, documents, meds, airplane needs.  

The Technique:  To actually pack the suitcase, roll most items, placing in one at a time and fitting to the spaces.  Don’t fold, stack, and try to place entire pile in as a unit.  Tuck socks and undies into shoes.  Put raingear in first, sleeping attire on top.  Larger items in first, centered, and smaller items rolled along edges.  You’ll be amazed how much you can fit in.  Keep reading for tips on choices…

>SHOES
Start wardrobe planning with shoes (I can't say enough about footwear importance).  2 pairs plus flip flops or crushable sandals:

First pair - good quality waterproof walking/hiking.  Wear this heaviest, bulkiest pair on the airplane (yes, it’ll take an extra minute in the security line).
Second pair - back-up that can be used to give feet a rest from first pair and when first pair get wet or muddy.  Still need to be able to walk around London all day in this pair.  There are some good packable options out there. Lastly - flip flops or sandals for pool-side, dirty showers, beach wear, around hotel.  Water shoes or Teva types good option here too.

NEVER take new shoes on a trip.  If you buy something - do it at least a couple weeks in advance and wear them a lot before departure.

>CLOTHING
Stay with a two-color system, with an accent color for variety.  Black and white with yellow or red.  Khaki and navy with red.  Green and brown with gold.  Make sure all tops go with all bottoms for maximum combinations out of minimal pieces.  Look for reversible and convertible pieces—ie. zip-off pants and reversible knit cold weather layer in two colors.  Choose a good quality rain parka with hood and drawstrings for outermost layer.  No jeans - they pack thick and don't dry readily.  Scrutinize each piece for usefulness and packability.

Plan on buying local attire—a Mayan blouse, a Hawaiian shirt, a sari—and feel locale-connected.  And plan on washing, especially socks and undies, along the way.  Or another good strategy—bring items that are on a one-way trip'and just leave them behind.  Often someone in your host country will be glad to get them (or undies that needed discarding anyway) and then room for souvenir purchases magically appears!   

>LAYERS
Layers are the key for dealing with weather variations, rather than carrying a big thick coat (unless taking an Antarctic or more extreme trip).  Start with warm weather layer and work outward:  t-shirt or tank top first, then short-sleeved shirt and/or long-sleeved shirt, then warm layer (fleece, hoodie, reversible sweater, etc.), then rain jacket.  Don't start with a turtleneck (again, unless in a more extreme trip) because it's hard to take off later in day when it warms up. 

Pack for the best possible conditions, not the worst.  Hold every piece in your hands, and ask yourself not will you wear it, but will you wear it enough.
*See notes in PACKING LIST below for more tips...

OPTIONS: copy / paste / print - or download PDF here:

VALUABLES, DOCUMENTS
cash - small bills best, make sure they are clean of marks and tears
credit cards - two types, in case one doesn't 'go through'
travelers checks – optional, use as emergency funds and to convert
moneybelt - more in Cautions
drivers license – and International Drivers Permit if country requires (AAA issues)
airline tickets, itinerary, hotel and rental car documents/information
passport / visa documents
immunization records - if required, check carefully
photocopies of above - trimmed and kept in separate place
addresses / phones / email / emergency contacts / embassies—both home and abroad - check US Dept. of State International Travel
language book
guidebook / maps (cut out appropriate sections only, trim)
novel / journal / ebook reader, like Kindle (can hold guidebooks, too) / magazines

GEAR
suitcase, daypack – see Equipment
luggage tags / TSA locks
binoculars - see Equipment
pouch or case / safety chain / raincover / lens paper or cleaning pen
bird book, destination checklists and where-to-go information
scope / tripod – optional, see Equipment for discussion

HANDY STUFF
pens, pencil, notepad
antibacterial wet wipes, singles pack
airplane snacks
baggies - few large, few small, myriad uses
bungee and/or rubber bands and/or paper clips and/or bit of duct tape
thin nylon cord for clothesline
alarm clock - travel style
watch - cheap, w/ new battery or windup type
extra batteries
compass - small, zipper clip-on type
water bottle – empty, until through security
plastic fork / spoon / can opener (may get confiscated)
flashlight - small, or penlight
nylon or net bag - flattens to almost nothing, for souvenirs, dirty clothes, etc. 
sewing kit – optional, without scissors
deck of cards, travel games

ELECTRONICS
cell phone / charger – check roaming charges
netbook / charger  - optional
flash drive or small hard drive device (for digital pic storage, etc.)
camera / video camera / battery / charger / cables / lenses
car chargers  
MP3 music/birdsong system (can be on smart phone) / earplugs
GPS, Navigation aid (Garmin type or smart phone)
outlet adaptor / voltage,current converter (ck for country visiting)

PERSONAL NEEDS, CLOTHING
toiletry case - thin, waterproof 
3.4 ounce bottles in 1 quart clear baggie for toiletries (1 baggie/per person)
shampoo / conditioner 
soap - liquid works well
toothpaste / toothbrush / floss
brush/comb
first aid kit - small, combo of: antibiotics / antibacterial cream / cortisone / Pepto / Imodium / pain-reliever / Ex-Lax  
vitamins / personal RX
sunscreen
insect repellent - no aerosols, look for stick type, see Cautions
Kleenex - couple travel packs, handy for toilet paper at destination
nail clipper / file (optional, can get confiscated)
shaving needs, vaseline
for women:  feminine items / pocket mirror / lotion / hair clips or bands  
make up - minimal 
jewelry - minimal and not irreplaceable
eye needs:  contacts, solution / reading glasses / sunglasses / case
raincoat - parka style with hood
rain pants - thin nylon
hat - crushable
swimsuit - men can use zip-off pants
(tankini type works well for women – top can be worn alone)
sarong, thin rayon-type – many uses (cover up, skirt, blanket, shawl)
scarf/bandanna - many uses
shoes - 2-3 pairs, see Packing Tips above
pants - 1 pair chinos (for airplane), 2 pairs cargo or zip-offs
shorts - optional / use zip-offs
skirts - 1-2, depending on preference, good for airplane
t-shirts - 2-3 
shirts - 2-3 long sleeve, 2-3 short sleeve
sweater/warm layer - choose carefully - make sure thin and packable 
socks, undies - 4-6 pairs / bra - 2  
belt

KID STUFF  (limit to what child can carry in own daypack):
small toys / games / cards 
handheld game device / charger or batteries 
books
snacks
small sketchpad / colored pencils / little sharpener
Beanie Baby friend (not irreplaceable)
small ball or nylon fabric frisbee 

OPTIONAL, FOR SOME TYPES OF TRIPS (not all carry-on items):
tent / ground cloth
sleeping bags / pads
snorkel gear
harmonica, penny whistle, guitar
insect netting – head cover type or small tent type for babies
laser pointer
walkie talkies
gloves / stocking hat
towel - optional, thin packable hand-towel size
bowl / cup
vest - birder's type, w/ pockets
compressor bags, if packing bulky items like sweaters, coats
rubber boots or pullover types (that fit over shoes)