Where is it useful to work first for neat colour filling in a square shape?

Correct answer: Near the edges and corners

The governing technique is controlled edge filling. Working carefully near the corners and boundaries first establishes the square’s shape and prevents paint from crossing the outline. Once the edges are secure, the larger central area can be filled with broader, more confident strokes. Therefore option C is correct. Starting only in the centre does not control the boundary, while painting outside or on the back of the paper cannot produce a neat square.