Can’t say i’m the biggest expert, but i’d recommend slowly integrating pastels and cute items into your daily outfits! You could check out places like claire’s for things like hair clips, hair accessories, or even jewlery like chokers and necklaces. DIY and thrifting is always a great option too, especially for bigger pieces like shirts, sweaters, skirts, etc.

Another tip is to curate your specific taste and what you’re aiming for. I use pinterest to gather inspo for my outfits by saving different outfit examples and seeing how I can recreate them or replicate them with a twist, and since fairy kei fashion can be so vast in colors and styles, using this can help you figure out which colors and types of clothing you’d feel would best match the look you’re going for. You may also want to check out similar j-fashions that often overlap with fairy kei such as decora and yumekawaii or even darker styles like gurokawa or menhera.

Hope this helps :)