Just practice.

       I have a sort of love/hate relationship with white Flowers I love to try shots of them they HATE me trying to and conspire against me - frequently - SO - I keep trying.  It also fills an uninspired "what shall I shoot?" moment.
       There are those who mistake these (Leucojums) for Snowdrops.  I suppose, really, it's an understandable mistake; they come up more or less together and aren't all that dissimilar; Leucojums apparently have a common name of "Summer Snowflake" I think too.