Radiator heat balancing?

Question:What is the most effective way of balancing all radiators in the house so that they give out about similar heat...at the moment my furthest radiator is not as warm as the rest of the others in the house. Is it a matter of using the individual thermostat valve control ? or does each lockseal play a part? Any advice would be appreciated, thanks.

Answers:
well to start with if you have free standing radiators they should have bleeders on them they need to be open at least every two months if not more they get air in them that's about all you can do with the maybe install a can vent on the farthest one from the boiler that will bleed them autumaticaly if not a heating person may be in order