Since your business is related to fashions in Nigeria, I would suggest you review some of the links online that are related to the fashion industry in Nigeria:
https://www.entrepreneurs.ng/how-to-start-a-fashion-business/ | https://businesshab.com/top-ideas/clothing-business-in-nigeria/ | https://www.entlifeonline.com/how-to-start-a-fashion-design-business-detailed-guide/
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to be successful, startups shouldn't just try to be a scaled-down version of a large company. For existing companies with a known market, traditional product development can work just fine. But if you're unsure about what you're selling and who you're going to sell it to, a startup model might be more appropriale.