What sort of things are you thinking of decluttering?
I find organising things and grouping the same items together helps. So all my cleaning stuff is together, I didnt have to buy any for months as I was going through the excess. This year I didnt buy suncream as I gathered it all from various places and used it up (still got more!!) Ditto cellotape I havent bought any since I sorted about a year ago, I had so many in various places!
I have a bookcase in my lounge with plastic boxes on, one for sticky things (tape, bluetack etc), measuring and fixing (tape measures, multi screwdriver, command hooks), cat stuff, etc. Under the sink has boxes of different things. In the loft is a birthday box (candles, paper plates, banners, wrapping paper, cards)
I've saved money this year just using up what I have as it's grouped together and getting used rather than me buying new as I cant find the old ones.
As soon as dds outgrow things I get rid. Straight to charity shop or on facebook marketplace.
Be realistic how many of a thing you really need, I decluttered the bedding we had at least 6/7 sets for each bed. That's way too many, we now have 3 per bed (one on, one washed and a spare Incase of illness) Cups and glasses, we don't need loads as we wash up every day and don't have huge parties (if I did I would use paper cups!)