slip & turn
Part of the problem here is that modern PLOG systems are very good at forcasting the fuel burn and in some cases are within 20-30kg of what happens, what most seem to over look is that the D+E/CMR (final res +alt) is in many case the very worst case you'll see as more often than not you will use less than planned fuel (ATC are much more focused on giving you direct to these days) and as was said eailer you'll have the contingency fuel on top.
Also most systems that generate plogs use the longest SID/STAR couple and dont take the weight of children (35kg) into account only adults (70/88) so the EZFW will often be at least 1000kg higher on a typical med run than the actual ZFW which will reduce burn.
I will go further: there is so much fat built into these systems that if min plog fuel 9007kg and its a nice day(wx,timeof day, route,airport)i am more than happy to take 9000kg (by reducing taxi burn) after all in the case of the classic how are you going to put 7kg in the centre tank? then how are you going to use it?
Over the last 8 years i have only ever ended up with less than CMR/D+E on 2 occasions once after a divert (having held for 40 mins) and once holding overhead destination with an EAT in good weather conditions and using my Alt fuel to hold (all safe & legal)