If wx is good but I may expect some traffics or higher runway occupancy time due to closed taxiway or wip, I will take up to 500 kgs extra. As others said above you know more or less about your area and destinations. Some routes are very busy and sometimes you will be maintaining up to 5000 feet below the optimum level.
My company allows us to bring as much fuel as we want but just need to write the reason, but if one day the chief would say "wx is good, carry only minimum fuel" I will do that and I will fly normally (because everything is legal and safe) In case of unexpected event occurs, I will declare minimum fuel or mayday fuel as needed.