What to look for in chrysanthemums
Count the rows
A chrysanthemum is density before it is anything else. A real pompom carries hundreds of short petals in tight concentric rows. Thin versions cheat by leaving a gap at the back and facing the flower forward, so look for a photograph taken from the side rather than head-on.
Regularity is not a fault here
Unlike a rose, a chrysanthemum genuinely is symmetrical, so the usual advice about irregularity does not apply. Judge it instead on whether the head stays round from every angle and whether the colour deepens slightly towards the centre, which is what a real one does as the inner petals stay closed longer.
Round shapes work in threes
A single pompom in an arrangement reads as an accident. Three or more, at different heights and in two sizes, read as a decision. This is why craspedia and billy buttons belong on the same page — they are the same shape at a smaller scale, and they are what stops a row of pompoms looking like a row of pompoms.