A few things can change how much you have taken out.
1. you still can ask for a flat extra amount to be taken - that line didn't go away
2. don't claim any "extra" deductions (this would be in place of the standard deduction)
3. "claim" extra income - there is a new section around "other" income to help out people who have income that they don't withhold taxes on (like interest or stock gains). You can put money here and when they do the calculation for your tax they will "add" this to your annual income.
