I do this at the end of summer and end of winter every year - I vacuum pack away a lot of things and put them on top of the wardrobe.
Take absolutely everything out, lay it on the bed, then sort it through.
Stuff you wear all the time, definitely keepers. Put it aside.
Stuff you haven’t worn for a while - try it on and see how you feel. Keep/charity/chuck if not feeling it, it doesn’t fit perfectly, or it’s damaged in some way and can’t be saved.
Put things back in. I tend to group items together - eg, jumpers at one end of the wardrobe, trousers and dresses at the other, jeans and skirts on the lower section, t-shirts and tops in a chest of drawers.
Make a note of any gaps where you need to replace stuff - eg, black polo neck jumper too bobbly, but essential work item.
Pre-Covid I thought on my wardrobe a bit like a pie chart. So work (for me) four days a week = smart casual. Not work days = jeans, tops, jumpers, trainers etc, dresses for going out for lunch/dinner etc. Home in the evenings or quiet weekends = joggers, jumpers or t-shirts depending on the time of year. The ratios should, in theory, balance out - no point in having a dozen fancy frocks if most of your time is spent doing the garden or walking the dog.
Now I mainly work from home, and never go out!