Choosing an icon style that scales with your product

Most icon sets look fine in a design file and fall apart in the interface. The usual cause is optical size: a glyph drawn at 48px and scaled to 16px loses the very details that made it readable.

Pick a stroke weight and hold it

Mixed stroke weights are the fastest way to make a set look borrowed from three places. Decide early and apply it everywhere.

Draw for the smallest size you ship

If 16px is your smallest, draw at 16 and scale up. The reverse never survives.