If you're moving house, you need to think about how to prioritise the fish tanks. As Andrew said, you often wind up with other priorities and the fish take a back seat. Next thing you know, you're exhausted, finally figured out where your bed is going to go, and the fish are on day three of living in a rubbermade tub. Set up some good stock tubs, buckets, or similar to house the fish, and make sure they can live in these indefinitely -- aeraters and air stones, ammo lock, poly filter, etc. are all needed.
This time of year, temperature also plays a big part in it. You want to keep those fish warm on the move, and in the new place. The fish should be the last thing to go onto the moving truck and the first thing to come off. If possible, don't put the fish in the back of a truck -- transport them in the car or cabin with you.
Make sure you've emptied the fish tank completely before attempting to move it, and not just of water. Get buckets with lids to take the gravel. Don't try to transport anything inside of the tank -- one good bump and a rock can bounce, smash the bottom, and the end. Put the fish in buckets or bag them, and add a good dose of stress coat to their water. I prefer moving fish in buckets to bags, as you don't have to worry about packing and unpacking them. If you're moving plants, do not put the plants in the same containers as the fish -- they can let out some nasty juices that will poison your fish.
And, you really want to try to get that fish tank set up as quickly as possible. If you've kept the gravel reasonably wet, you won't have much loss of bacteria. Figure out where it's going to go, get it up and running ASAP. Make a mental check list of the stuff you need to set-up the tank, and make sure that they're together. Not just the obvious -- filter, dechlorinator, etc., but ... where'd you pack the Python, faucet adapter, buckets, etc.
Keep the tank lights off for a day or two at the new place. It'll ease stress on the fish. And, when you figure out that you don't like the tank where you put it, give it a week or so before you move it across the room.
If it's a short distance move, it's not a bad idea to leave the fish tank behind until everything is moved, then make a separate, special trip for it. Or, do this in reverse and move it first. You may also consider bringing the fish to a friend who has either a spare tank, or the space to set your tank up to baby sit the fish for a while.
It isn't unheard of to lose your fish in a big move, so before you consider it, take a good, hard look at your fish, and decide if it is worth the risk, worth the stress, and worth the trouble. If you've got a bunch of relatively easily replaceable fish, maybe the best thing to do is net them all a few days ahead of time, bring them to the local fish store, and donate them to the store. You can replace them in a week or two when things are back to normal after the move. (You may even ask at the LFS if they'll be willing to let you buy any of your fish back that haven't sold or are otherwise unavailable for a nominal fee).