Baby Wipes are essential, when you cant find a bathroom or tap to clean up you or your littlies wipes will do a great job also use them to clean surfaces that you're going to be touching that may not be very hygenic. Hand sanitizer is now widely available in shops, use it as often as you can to stop germs spreading.

For bulky items check out the numerous hire companies that now exist.  Look at the cost versus convenience of bulky items such as strollers, beach toys, cots, car seats and prams.

Consider buying some travel towels, they fold down to nothing and are the first item I pack.  They dry in no time and come in handy as a small blanket, towel, tablecloth, sheet and more.

If your luggage has seen better days consider purchasing a good quality suitcase with a fold out handle.  There are heaps of styles on the market.

Depending on your destination and style of holiday, you may need a good travel guide.  There is no better guide than the famous lonely planet travel guides, they cover hundreds of destinations and the lonely planet guides are available online at discount prices.

Due to the upgraded security precautions at airports don't pack any knives or sharp objects in your carry on luggage and don't joke when asked about the contents of your bag its taken very seriously by security.

Pack all the essentials in your carry on luggage, nappies, dummy, sanitizer, wipes and a change of underclothes at least, incase your luggage goes somewhere you're not.

Try not to pack more than you need.  Dress in layers, pack items of clothing that complement each other so you can wear a t-shirt, jumper and jacket or part thereof.  Remember you've got to carry it so be brutal with the "do I need it" process.

An umbrella or poncho type raincoats, just the cheap plastic throw over type.  They pack down small and are cheaper than having to buy raincoats at your destination if the weather turns bad.

Pack clothes that dont need ironing, you dont want to spend your holiday at the ironing board and if you pack carefully there is less chance that your items will become creased during travel.

Pack for the climate of your destination. 

If you're going somewhere with cheap clothing, like Asia, and you intend to buy new clothes then take as little as possible with you, shop when you arrive and then you'll fit your new goodies in your case without paying excess baggage
 
With toiletries, mini-bottles or sample bottles are easiest. Remember to pack them in a plastic bag just in case there is a breakage or leak. Rules for taking these as onboard luggage are very strict, for most items its easier to pack them in your checked in luggage or just purchase them on arrival at your destination. 

On your return pack your souveniers between items of clothing to hopefully avoid breakage or take onboard in your carry on luggage if possible.

Remember customs laws if travelling internationally.  If you have anything that will require clearance pack it in an easy to get to place to speed up your customs process.

But most of all pack your sense of humour.  Holidays are fun, smile a lot and enjoy every moment.

Buy what you need online at the following online retailers: