[Closed] International travellers -what carry on luggage?

Using a thule backpack that takes a 17" laptop and 3 days of business wear. However I check bags every time and put spare underwear in the hand luggage occasionally a shirt/t-shirt for long haul.

I was counting them up last night and I think it's about 50 flights a year at the moment and one bag has been late in 3 years - transferring oversized from international to domestic when I had to do a quarantine check on it.

Like flashy there isn't much waiting for bags or check in, normally within 10 mins either end.