Right, if it's very bad, I found the FlyLady 27 flings very good. You take a black binbag and go around your house and find 27 things to throw out. If you don't love it, need it or use it, out it goes. When you have put the 27 things in the bag, you go straight outside and put it in the outside bin, so you can't change your mind.
You can then go around and find 27 things to give away and go straight to a charity shop with them.
Repeat as needed!
With clothes for yourself, don't keep anything that is the wrong size, doesn't suit you, or that you haven't worn in a year. This can be hard if something was expensive but just let it go to someone who would use it
Clothes for kids, only hand down good stuff as otherwise you can end up with bagloads of the stuff which will be out of fashion by the time the youngest gets bigger.
Keep nothing that is broken, as you won't ever repair it!
Don't keep ugly stuff, just because some relative gave it to you. It's your house, not theirs. I had this recently with a piece of art given to me by a relative. I felt very bad about it, as she had put such a huge amount of work into it but it just wasn't fit for display. ( btw dsis if you are reading this, it was not your work, but someone elses!)
Hard I know, but you can do it!