Start with your refund check. Open up a retirement account with it, arrange with your HR dept. to to change your withholding, then deposit the increase from your paycheck into the account every payday. On top of contributing the maximum allowed to your IRA at work, especially if your employer contributes to it. You can never have too much money in your retirement years.
Well in my estimation you have already lost money if you are getting a refund check. Better to legally change your withholding numbers and your tax plan to instead of letting the government use YOUR money for free you get a bigger paycheck and take a bit each pay period and put it in a savings plan and then invest it in something better when you get enough for a buy-in on the new investment.