Controlling Central Heating During Winter? Combi Boiler?

I have a Worcester 24CDi BF Combi boiler with no room thermostat and no TRVS, just regular manual valves. What's the most efficient way to heat the house? Turn heating to max and use the manual valves on each radiator? Open the radiator valves and keep boiler setting low? Home has cavity wall insulation, double glazing, attic insulation and temp drops to around 11C - 12C indoors overnight in the winter, is that normal. I've heard people say you need to warm the house through to warm the walls and furniture to help with heat loss. Also think of installing a wireless room thermostat, any recommendations on basic models at good prices? Would a room stat be best?