Call around shops to see if they have only spare boxes they want to get rid off. Buying box packs can be expensive so the more free boxes you can get the cheaper it'll be. However we've always needed to buy some new one we've found that places like Clockwork also sells second hand boxes for £1 each and they are huge! Just make sure you ask if they do because I've never seen they advertise them!
Always check you are getting the best energy deal when you move. Places like Money Saving Expert are great places to check you are getting the best deal!
If your downsizing and you have way to much stuff to fit into your new house, there is always Service provider: Warehouse Storage Solutions Limited They have all types of storage solutions perfect for anyone's needs. Even if you need just a small item storing nothing is too big or small.
Once you have moved make sure you redirect your mail with Royal Mail! No matter how organised you think you have been there are still places you would have forgot to change your address. This is a great way of making sure you catch those that have slipped through the net!