In my airline, we prepare our T/OFF Perf. Page with the Estimated Take-Off Weight of our OFP while we have time and are not in a hurry to close doors.
We get an EZFW from our operations in order to correct our Fuel numbers (normally the maintenance guy is waiting for Captains finnal decision to complete the refueling process, that has stoped 2 tons before the initial estimated figure) as soon as we get to the aircraft. That estimate will show us a weight trend (compared to the TOW of the OFP).
When the Load Sheet arrives, the Captain dictates to the Co-Pilot the actual numbers. Actual numbers are therefore compared with the ones we have on our OFP and the Co-Pilot annouces to the Captain when entering the Actual ZFW on the FMGC, that we are "x Tons" below or above the EZFW of the Flight Plan. He goes to the RTOW's and finds the new V1, Vr, V2 and FLEX.
Closes the RTOW Book and hands it to the Captain. The Captain gives him a copy of the Load Sheet and finds his own speeds and Flex on the RTOW to compare with the ones just entered on the FMGC by the F/O.
During our Take-Off briefing we positively identify the aircraft we are flying that day. We fly 3 different types (lato sense) of aircraft: A340-300 and A330 PW or GE equipped (Different weights, different engines). As a general rule, it is a good help to check for two or three limitation items like MTOW, Max EGT, if that particular bird has Brake-Fans (or not) if it has Fuel Dump (or not). It helps you to sit in the right aircraft.
I understand that there is no panacea to avoid accidents. I'm very sorry for our colleagues.