I pack them away. Some in a wicker trunk at the foot of my bed, some in drawers in a freestanding wardrobe. I use those packing bags that compress them.
I was going to dig up jumpers this past weekend, but hopes for a predicted warm spell made me postpone doing that.
I don't really have many so I just leave them in the drawer. T-shirts and vests I wear all year round. I only have a handful of shorts and summer skirts. Summer tops can be worn with a cardi.
I tend to wear layers so I have one wardrobe all year round and leave them in the wardrobes ad drawers they live in. I have odd seasonal stuff like shorts and snoods etc but I have quite a large closet so I don't really have to bother with moving them.
All clothes go in the wardrobe/drawer and tend to be used in sequence. Only difference in that in warmer weather the thicker clothes tend to get skipped and in the colder weather the thinner clothes tend to get skipped.
For the first time ever I have put all my lightweight cropped trousers into the spare room wardrobe today.
I never wear dresses or skirts.
Have put on a lot of weight this year and having to buy more winter trousers :-(
Used to turn my wardrobe with the seasons, focussing on the on trend colours if they suited me, just updating with a few odds and ends. I don't have to do this now as I have an extra wardrobe and one and a half chests of drawers. Plus all the coathooks. It's an ill wind...