>>716511486
The red pieces are obviously hair, hair strands are drawn in arches. Find the curves that match up.
Lighter shades of hair usually go higher up with highlights.

You can start with grouping pieces that have matching colors / patterns, like the sky and that tile grid.
The less area you need to look at the easier it will be to find matching pieces.
When you stop finding matching pieces, shift to looking at piece shapes instead of their content. Swap back and forth as needed.
If you're really stuck, scramble the pieces and you will find things you missed.