I actually think you should do the opposite. If you have other investments & savings, only pull from them for what you need to supplement your SS payments.
Start with any pre-tax (such as ROTH IRA or nonqualified savings that you earmarked for retirement), and avoid taking from your IRAs or 401(k)s until later to postpone income taxation.
If you start using up your own money and die before ever getting any SS, then what you saved and set aside will be diminished and not available to pass along to your heirs.
If you need $3,000 per month, and can get $2,000 per month from SS, TAKE IT, and use only $1,000/month of YOUR MONEY. Otherwise, you are using $3,000/month of your money, in the hope that you live until your future date for higher SS.
Sorry, that should be “start with any nontaxable (such as ROTH IRA....etc.”
Not Pretax.