Since you are talking about reducing your late payment penalty by annualizing income, you'll have to show most or a large part of your income came at the second half or last quarter of last year. I found it would be easier if you can tabulate your income on a monthly basis (on a spreadsheet), then you have to add: 1) the first 3 months income (Jan-Mar), then the first 5 months (Jan-May), and lastly the first 8 months (Jan-Aug), then you enter these into Form 2210 (make sure you click on the supplement AI to enter these values). Once you do that, then Turbotax will fill in the rest.
