I'm literally in love. This is exactly what I have always wanted from a fashion game. I can't wait to see how far this game goes :)
I would love to see more options for patterns for more diverse types and styles of clothes, along with more accessory options and colours of fabric in the future. I would also love to see more complex patterns unlocked as you progress through the game. Perhaps this is a lot to ask, but in that vein, it would really awesome to be able to make clothes from many different points in history, and from different cultures. It would also be great to have options to design things like suits, pants and more masculine/unisex clothing for clients of all genders.
I also think it would be really cool to include a feature where you draft the patterns yourself according to measurements you take of your customers. It might end up adding complexity to what is supposed to be an easy-going game, but I think it would be super educational and realistic. It would also open up for the opportunity to add quests in-game where customers come in just to ask for alterations and/or upcycling of their existing garments, which could be a really fun way to exercise one's own creativity and would also give the quests in the game more variety.