Good metal spoons are well rounded, finely finished, and typically made of quality stainless steel.
The best design for the cross-section of a spoon handle is a horizontal oval, providing the stability of a semi-flat surface and the comfort of a continuous curve.
The 2 best general materials for the average spoon are metal and wood. Corrosion-resistant metal provides durability and ease of cleaning. Protectively finished wood provides quietness and thermal insulation.
Portable applications may demand tight weight-efficiency, in which case durable food-safe plastic is a good light-weight option despite its potential for thermal warping, brittleness, and UV degradation.
Safety and ease of cleaning are improved with a smooth surface finish that prevents substances from staying on the spoon.
The best weight balance leans toward the head of the spoon so as to prevent the handle from flipping out of cup-like containers.
The best handle geometry has a slight vertical curve near the end of the handle so as to hang on the edge of a bowl and prevent the handle from falling sideways.