Just let them carry on growing. Most varieties are only just starting to fruit now (I ate my first All Green Bush this evening
). They normally produce lots of male flowers first. The female flowers form on the end of tiny courgettes which will get bigger and bigger. Often the flowers die off long before the courgettes are suitable for harvesting.
I'm sure celebrity chefs keep banging on about courgette flowers because they're so difficult to harvest in good condition.
Paul