Moving from one host to another is both exciting and daunting at the same time. While you're likely moving to a new host because they have a better plan which offers your more performance, better features, increased stability, and the price that fits your budget there are a few critical steps you should remember to avoid causing yourself unnecessary headaches.
#1 Choose Your New Host Carefully
#2 Do Not Cancel Your Old Account In Haste
#3 Update DNS Records
#4 Alert Your Users Early
#5 Domain Name Registrar Changes
#6 I'm Changing Domain Names
#7 Test Everything Twice
If you have followed all of the steps described above and everything works fine there is nothing else to say but congratulations!