How do you Declutter?

Hi Mommies! I want to ask how do you declutter? Where do you send your used clothes or babies clothes? Where do you sell your brand new items and good as new items? Im a mom of twins so I have a hard time decluttering because everything comes by pairs. I have a lot of brand new toys tht were gifted but outgrown and a lot of outgrown brand new clothes. Already donated some to Caritas and other kids orphanages but some of the items left here are still good as new, so I really want to sell them so I can save up for the twins. #declutter #declutteryourlife