How Do You Inject Personality into Ultra-Minimalist Design Without Adding Visual Clutter?

I'm currently designing a new office space and I'm committed to a sleek, ultra-minimalist aesthetic for productivity. However, I'm finding it incredibly challenging to make the space feel unique and inviting without resorting to decorative items that would break the clean lines. How do designers achieve that balance of personality and strict minimalism? I'm genuinely curious about specific techniques or elements that work wonders here!