DoingItMyself method with clothes:
The first time...
Empty all wardrobes, cupboard etc of clothes, pile them on the bed. Even if the pile touches the ceiling.
As you pick up each item to find it a suitable storage place check...
Is it in good condition? No - into a bin liner. Yes? Ask
Does it fit?
Is it comfortable?
Do I feel great in it?
No to any of those and it goes in the bin liner, or into a carrier bag for things destined for the charity shop.
If it survives, it can go to an appropriate wardrobe or drawer.
Warning: Do not be misled by thoughts such as 'But it was so expensive!' or 'I might need it in ten years time.' Bin-liner or charity bag.
There will be 'keepsake items', like my wedding shoes. Move them to where you store keepsakes.
When you have been through everything and you have about one-fifth of your original hoard left, have a cup of tea then start again.
The second time...
Put clothes together in outfits.
Anything that isn't part of an outfit either goes into the charity bag(s) or you start your list - you'll need a few specific new items to complete outfits you already have.
When you've finished that, you might have shed a quarter of the items that survived the first sift.
And now you have neat, tidy cupboards and drawers containing only clothes that are in good condition, fit, and you feel good in. You should have also a brief list of a few extra things to shop for.
Have another look. Do you need to make major investments? Boots, coats, one or two good suits? Depends on your lifestyle. But you are now in a position to spend wisely if you have to spend.
The great advantage of this method is that from now on, every time you get dressed, you can feel absolute joy in what you are wearing.