When you are writing, there's broadly two types of imagery- abstract and concrete.
Abstract is conceptual, so thing like love, victory, kindness- ideas that aren't necessarily grounded in the real world.
Concrete is things you can physically feel, touch and experience. So a rose is a concrete image when love isn't. (although a cliched one).
Concrete imagery tends to be better the more specific and vivid it is.
A good way to focus on the concrete is to use the five senses