For the next 7 days, remove 5 things from your house each day. Find 5 things each day that do not bring you joy and get them out of the house. Take them to a charity shop, bin them or sell them online. Just get them out of the house in the next 7 days.
Be mindful that you don’t discard someone else’s favourite item. If it is not 100% yours, do ask the other person first to see if they are ok with letting it go.
Secondly, really limit what you bring in to the house. Leave it out front for recycling or in the trash bin if necessary. The less you bring into the house, the less you need to throw away later on.
If you do this every day for three months, you’ll have gotten rid of 450 items and your house will be nearly free of clutter and feel very cozy and calm.