Honestly, if you have a skip, don't complicate things by sorting into piles to recycle, donate, etc.
Just fill up the skip and be done with all the stuff you don't want or need any more.
Charities can barely cope as it is with a fraction of what is donated. You're just kicking the can down the road, offloading your keep/ dump decisions on the charity instead of making them yourself.
Start with your kitchen.
If you haven't used cake / pie pans, utensils, or plastic storage items in the last 6 months, dump them.
Also, get rid of things that are broken, cracked, rusty, blunt, etc.
Go through your sauces, herbs, and spices and dump everything that's out of date.
Go through your tinned foods and stuff like pasta, ride, dried beans - anything close to expiry or beyond, dump.
Go through your cleaning supplies - dump all but the bare minimum. Dump all cloths that are literally rags.
Dump all your extra mugs / novelty stuff.
Dump all novelty items, souvenirs from Butlins or wherever.
Dump all broken appliances.
Drawer full of bits and bobs that might come in handy - empty and dump all bits and bobs.
Next up, bathroom:
Dump all rarely used cleaning supplies and bottles with very little left in them. Keep the minimum, only what you know you'll use.
Dump all shampoo, conditioner, moisturizer, and other toiletry products that have less than an inch or very little left in them. Dump all little slivers of soap.
Check your towels, washcloths, and bathmats - get rid of all that are worn, threadbare, stained.
Your hall:
Sort through the family's coats and jackets, hoodies, tracksuit tops, etc. Make decisions based on what you truly need. Be ruthless.
Same goes for hats, scarves, gloves.
Ditto footwear. Get rid of items that are worn, down at heel, in poor shape, uncomfortable.
Throw out old/ broken umbrellas, tote bags, etc, that you don't use. Keep the minimum. Check stuff like skates, bats, balls - do the kids want to keep them...
Dining room/ sitting room:
Anything that's broken, stained, or that you haven't used for a while. Knick knacks you're tired of dusting, that don't mean anything to you. Anything you just plain don't like... Dump.
Candles and other decor you don't like/ want - dump.
Bedrooms:
The main offender here is usually too many clothes and too much spare bedding.
If there are clothes you're keeping for yourself 'for when you lose weight', dump.
If there are clothes you haven't worn for 12 months, dump.
Clothes your children have grown out of and can't be passed down - dump.
Children's clothes that are holey, very stained, anything that likely won't be worn again, dump.
More than two sets of sheets/ duvet covers, pillow slips per bed - dump.
Old, grungy pillows - dump.
Make up - sort through. Only keep what you love and need.
Perfumes - same.
Jewelery - same.
Toys: the children can help decide what stays and what goes. Err on the side of caution where toys are concerned. Children can get upset when they realise the finality of a clean out and it's too late to get their stuff back.
All the same, there might be a good deal of junk, little items from happy meals, small pieces of tat, and they take up space.
May or may not apply -
Books:
Keep children's books if there's any doubt.
If you have a lot of books, maybe dump books you've read, books you've started but didn't keep reading, books you know you'll never get around to reading, amything you can get via Kindle.
( I personally can't imagine ever getting rid of books and I'm not a regular Kindle user.)
Old cords, chargers, electronics no longer used, incl old phones - you may need to find a special electronics collection facility. Don't get rid of anything that ever had personal/ financial information on it without getting it properly wiped first.
Craft supplies:
Any stash of yarn, fabric, patterns, collage supplies, beads, paints, brushes, embroidery threads, etc - decide what's reasonable to keep.