If you have a lot of decluttering to do and don't know where to start, break it down into more manageable segments like choose one drawer, or a closet shelf. Empty the drawer or shelf. Then,
before putting anything back, take each item and decide if you use it, love it and if not give or sell it to someone who will. If it belongs elsewhere, take it there. Doing one small area at a time helps get the energy flowing and you will be energized by it.