From previous experience the guys I have had have been very friendly and professional. (No I don't work for CASA)

They hovered around until the Pax were escorted off the airport then came over introduced himself and gave me the speel about being from CASA and this being a random check blah blah blah
From memory they want:
License, Medical, Aircraft Manual, Airworthiness Certificate, Checklist, Emergency checklist, MR (checking hours and cross checking items written down), DAPS, ERSA, WACS, TAC, VTC, currency of all of the above, asking how much rest in last 24 hours, time starting work, duty hours, check your approvals in license, flight plan, Ramp weight, TO weight, Landing weight, fuel burn in KGs, empty weight, pax weights and freight, DG's and paperwork, fuel reserves, catergory of flight, CG and will get you to cross check it for them, carriage of survival gear (if required) Fuel log (if needed say on a piston) weather and notams, winds in the flight plan, seat belts, child seat belts, checked the pressurisation system and the oxygen masks and probably a 1000 other things that I have forgotten by now!!! Anyway they were pretty through.
My suggestion is that you just leave everything in the flight bag thus you can't get caught out on leaving the old license, or DAPS behind trick!! Also having a good manifest system and making sure the company has the right documentation in the aircraft will also cover you for most things they want.
I have had friends who have been pinged for:
no license with them, MR problems, out of date maps, and have heard of someone getting done overloaded (whoops!!!)
Have also heard a good story about a crew getting done for not having enough reserves because the CASA guy thought that Special Alternate Minima was something they had made up to cover them for landing without fuel for an alternate!! Suffice to say that about a week later that had the non compliance item removed, but no apology was given!!!!!!!! Makes you wonder!!
One of the guys I had once couldn't understand the concept of an aircraft being landing weight limited!!!!! He wanted to know why the MTOW for that sector was different to the one he had in front of him in the manual. I then had to go and explain why the TO weight changes depending on the length of the sector!!