1. Withdraw your interest and dividend from your taxable accounts, interest is taxed at your ordinary income rate, but your dividend is taxed at lower capital gain tax rate, 0%, 15% or 20%.
2. If you have maturing bond and CD, cash in them.
3. Sell your investments from retirement accounts 401k or 403b,or from Rollover IRA to generate cash. These retirement accounts have RMD when you reach 73. If you don't withdraw when reaching RMD age, the penalty is up to 25% of RMD amount.
4. Withdraw from your Roth IRA as a last resort.