Not an expert etc etc
I recently completed an incredibly useful exercise suggested by a writing/editing tutor elsewhere. (I will post the link below because credit must be given.) I found it helped me nail the ‘essence’ of my book brilliantly.
Summarise you book in 250-500 words – whatever!
Now summarise in 100 words
Finally 25 – and there’s you’re elevator pitch. Worked for me anyway ;)