sperzz: I prefer to travel light (especially if we have to handle the kids), so I usually pack only 1 set of clothes/day for the kids. For #1, I pack as much for her as I pack for us adults, nothing extra. For the 2 younger ones, I pack 2 extra sets - 1 in the luggage & another in the day bag.
My HB's practice is to pack based on what we think we need, then remove 1/3 of it! This is especially for longer trips of beyond 5 days. I remember when we went Europe, I insisted on bringing along for fear of the cold weather. He lets me bring mine & #1's stuffs but insisted I remove half of his. In the end, we really ended up using only half of what I brought... ops...
Now, I just adopt HB's mindset - we are there to enjoy, dun b bogged down by heavy luggage or the burden of having to look after excess luggage.. at worse, just buy new sets of clothing if we really ran out.
For our OZ trip this Jun, we are planning to make use of laundry services available. No need to lug so much clothings. In fact, I'm considering weaning the 2 younger ones off milk intake in the day time or to give fresh milk. Then we won't have to lug thermos & milk bottles etc. Just leave at hotel & feed in morning & night only. That would lighten up our day bag by a lot more... kekeke.. cos water bottles for 3 kids plus ourselves is already quite a load.
Diapers & milk/snacks supplies wise, I tend to bring slightly more - for fear that the kids may not get used to what's available at the destination.
Then if hygiene is a concern, can consider getting those sanitised disposable cover for toilet seats, those that u just place on top of the seats so our bums do not come into contact with the public toilet.
So exciting, your trip is just another day away!