When I first started travelling in Business Class, I thought Woohoo! no need to worry about packing anymore. I can take two giant suitcases, and just chuck stuff in, and never go over the weight limit.
No more packing angst over clothing and shoe choices.
Its not about size
It didn't take long to realise that it wasn't about weight or size or number of bags, but about what you can wrangle through an airport and into a hotel - comfortably.
International travellers who just take carry-on are liars
It's slightly different if I'm travelling with my partner or alone. Alone on international flights I can't do just carry-on. I read all those business frequent flyers saying they just take carry-on and a pashmina, but i'm sorry, I just don't believe them. If they are telling the truth, then they are those passengers, usually Americans, that have to ask three people to help them get their oversized cabin luggage (which should have been checked-in) into the overhead locker - all three suffering workplace injury in the process. It is just downright impossible to get a weeks worth of clothes, let alone gym shoes and kit, as well as your wet pack and computer to come in under 7 or 10kg. It just is. The case along probably takes 2 to 3kg.
I can usually keep my luggage to 15kg check-in and 9kg carryon, and that's including a laptop.
Occasionally if travelling with my partner we have another check-in suitcase - usually half empty - especially if our trip will take us through multiple seasons, and/or a particularly good shopping destination, but if possible we try to avoid that.
Model independent traveller
A good friend of mine, now of retirement age and an avid traveller often travelling in Business or First has learnt the wrangling rule. She now has the perfect backpack and checkable luggage of minimum weight and size, which is tried and tested to be wrangle-able through the worst of developing world airports. She has to be able to lug it in and out of overhead luggage lockers on aircraft, get the case comfortably off a luggage belt, and be able to load it into transport, and carry it up a few flights of stairs at a hotel without getting short of breath. There is no way she is relying on others, or risking strain to her limbs or back.
I'm younger, male and stronger, although not necessarily more fit - but I have taken her lead. You need to be able to wrangle it all yourself without a luggage trolley, or a porter. It makes for less stress, and a quicker departure from the airport. It also makes me less anxious - you only have two things to worry about: what is on your back/over your shoulder, and what is at the end of the handle in your hand. It also means I misplace less. If its not in one bag, its in the other, or I lost it.
Take your time and layover
As I have more time to travel, I have adopted the 'layover rule'. Depending on the hour of the day and duration of the layover, I often choose to do an overnight, despite usually travelling in anything but economy (coach). Whereas a six hour layover seems interminable and is guaranteed to make me grumpy however nice the lounge, a layover with a night in a nice hotel room with comfy bed, and of course a shower is something to look forward to.
Practice what I preach
We are travelling to the Europe from Australia later this year. We chose Vietnam Airlines in business, mainly to do with cost, and their new Boeing 787's. The cost is somewhere between a half and two-thirds of a normal business fare. The layover times are dreadful - 9 hour layover in Ho Chi Minh leaving at 1:45am, so we are doing an overnight, with late checkout. I'm thinking leisurely breakfast, pool, spa treatment and dinner before the overnight flight. And despite going to a northern hemisphere winter - it will be a one check-in bag job - OK maybe another case between us, just for the thermals in Norway and the Xmas presents. But they will all be in the wrangle-able spectrum.
Have any hints for keeping your luggage under control?