This mod works with the Fashion Sense framework and the supplementary framework FashionSenseOutfits.

To use Fashion Sense in-game, you will need the Hand Mirror item: when starting a new game you can tick the "start with mirror" box on the farmer setup screen, and with an already existent game you can buy it at Pierre's (iirc 2000g). Left clicking while holding the Hand Mirror opens the Fashion Sense menu, which allows you to override any and all parts of your look with clothing items / accessories from your installed Fashion Sense content packs. Look for them here: https://www.nexusmods.com/stardewvalley/mods/categories/13/ and here: https://www.nexusmods.com/stardewvalley/mods/categories/4/, or go to the Fashion Sense mod page, open the "Requirements" section in the description and go through the "Required by" part of it. (Make sure the packs you're downloading are for Fashion Sense and not something like Get Glam, and that they work with the current version of the game. Some of the top is last updated in 2017)

The Fashion Sense menu includes a "dresser" button, which opens the wardrobe menu where you can save outfits. This is what you'll need for this mod to work.

Step by step:
1. Download the frameworks specified above, then download content packs with hairstyles/accessories/clothes you want.
2. Acquire the mirror in-game.
3. Create the outfits you want this mod to switch you between and save them under any names you want.
-- note that if you set up an accessory in one outfit and then change to a different one that doesn't have any accessories set up for it, the accessory will carry over. This is reasonable behavior for something like elf ears - set up a bunch of outfits without them, then the last outfit with them, and enjoy elf ears in all outfits - but not even remotely so for something like a raincoat. Make sure all your outfits have at least one accessory! Add a belt or heterochromia or something.
4. Close the FS menu and put away the hand mirror. You don't need to carry it in your inventory except to change the outfits you've just set up.
5. Open the mod config and go through the settings to set them up to use the outfits you created.
-- note that the config is global and not save-specific. If you want to switch between multiple saves with different wardrobes (wardrobes are save-specific by default, though there's a "share outfit" button), you'll need to either use the same outfit names in all of them (such as the default ones in the config) or change the config every time you load a different one.
6. If you want to also use portraits and haven't set them up yet, now's the gime to look at the Portraits article!!
7. You can change the config and the outfits in the hand mirror any time you like!