I take a few bottles that I feel fit the location and situations I'll be in, then I take a LOT of samples that cover all range of moods. Although sometimes I try to go for a theme (like citrus) then try to get all ranges of that theme. It usually also depends on how fickle I feel, how needy I am, and what the situations I know I'll be going into make me feel like. For example, for going to the midwest in deep winter for a funeral, I couldn't take enough cozy, cuddly, warm, and soothing fragrances. (Although sometimes I'll throw in a direct opposite of my theme just because I am fickle and tend to be contrary--and it usually goes that on the days I think I most want something cuddly I need something sharp and piercing, or sometimes I think I want citrus and instead I need soothing, etc.).
Fireflies is always perfect in summer. Always.
(And, not too oddly enough, so is Luminaria.)
