Create a budgetThis might seem obvious, but it's so important. You need to know exactly how much money you have available to spend on the trip. Try to plan your trip for less than what you have budgeted. That will give you a little cushion for "just in case." Don't forget to include any expenses you'll have when you arrive (setting up your house, registering your vehicles, stocking your pantry, etc.). If you think it will take you 3 days to get to your new destination, budget for 5. You never know when you might have a flat tire, get sick, or be stranded somewhere for longer than expected.
Decide what you really, really, really need to take.
If you're on the fence, don't bring it. Sell or donate as much as you can. What you save in moving expenses can be used to repurchase anything you might need when you arrive.
Micromanage your credit cardsCheck your balances often. Keep an eye on your activity. Always know how much you have left and how much you will need.
Bring the essentialsI'm talking about a couple rolls of toilet paper, some plastic trash bags, hand soap, and paper towels. There's nothing worse than arriving at your new apartment with a full bladder and no toilet paper!!!
Don't forget about your medicineMake sure your medicine and other important items are easily accessible. Also make sure your prescriptions are up-to-date and that they are easily transferrable. Have your doctor and pharmacy in your phone contacts.
Have you moved across country? Do you have any other tips to share?