International or Domestic? HLO or checked bags? Length of trip? Hot or cold destination?
When I'm travelling J to overseas, in HL I've got enough electronics to drive the Death Star (laptop, chargers, universal power plug, iPad, back-up drive, UBS sticks, spare batteries), at least 1 day's change of clothes, at least 1 weeks prescriptions (plus the prescription), plus general toiletries, paper copies of itinerary & passport, business cards, e-tix, climate-determined extras (bathers / gloves/scarf). Plastic bags of various sizes. Basically so you can go to your business meetings / destination plus social for at least 24 hrs without any checked luggage turning up.
Plus hard copies of business related papers. Printing on the run - in lounges and even hotels - can be difficult. Actually, for visiting any 'lesser developed' country, where I'll be doing writing etc on the road, I take one of those compact printers, plus paper. An absolute god send - you can print your own stuff, in your room without relying on the wrenched 'business centre'.
If you are going to anywhere remotely 3rd world, take a proper travel medical kit (available from travel doctors/clinics). It has the industrial strength anti diarrhoea goodies and other great stuff. I actually take this everywhere I fly - 'be prepared'
If I have a checked bag (at least 23kg limit) I usually struggle to fill the weight, even for several weeks of trip, unless there are a lot of business papers / books. If I'm checking a bag, I'm a 'take it just in case' guy, rather than minimalist, but I still struggle to fill a 23kg case (except when I take the printer & paper
).
You need to watch taking some Australian allowed prescription medicines into certain countries (I think the Emirates / Dubai is one).
Don't take anything which it may appear to immigration that you are going to 'work' there (as opposed to visiting on 'business'). 'Work' has different meanings in different countries - and it doesn't just mean you are going to earn money. Try to check out if your country of destination is particular about certain business types. I'm in mining, and always get grilled when trying to enter Canada - they don't want me 'working' there, as they have enough of my kind already! Sometimes I get sent to secondary screening to prove I'm not going to 'work' during the visit. If they happen to open your bags, and see 'tools of the trade' - it makes proving that you aren't going to 'work' that much harder.
Hope that helps a bit.