Coolant and Thermostat Change

Changing the coolant on a 2002 Peugeot 406 HDi 110 with the 2.0 DW10ATED engine. The car was not overheating, or loosing water i was changing the coolant just as a routine service item, and while i was at it i changed the thermostat also. If there is any other things that could have been done differently please say so in the comments.