Glancing Girl here …
Anthropologie published a helpful tip list for mixing & matching:
1. when experimenting with patterns, anchor your look in a single color like crimson.
2. similar prints, different scales? mix subtle and substantial.
3. a dotty, black-and-white dress makes a crisp canvas for bold, brushstroke flora.
4. when rendered in complementary hues, a zippy plaid meshes with thin, delicate stripes.
5. flowers and stripes also go together ~ especially when they share a common color like navy.
6. when cross-pollinating floral patterns, use earthy neutrals to ground neon brights.
I’m planning on doing some substantial mixing with my wardrobe this summer …