If you are moving house to a smaller property, take a long, hard look at your possessions as you will most likely have to get rid of a sizeable portion of it. A good way to do this is to divide your belongings into groups. One group should consist of things that you need to take with you at all costs, then another group is stuff you could probably do without. The easiest way to get rid of these things is to simply give them away or take them to the dump.
Cutting down on the volume of items to be moved will make a big difference to your home moving costs, as you may find your mover needs to use a smaller vehicle and/or less men to handle your move.