No, I'm not writing the start of another novel - just dreaming of completing several - but next time I do I'll refer to the advice of Susan Hill.
"The first words are important. They lead the reader in. BUT there are many novels which I not only love and re-read but regard as very great novels, whose opening lines are nothing special. They do not go flash/bang, they do not show off, they are not clever. They lead the reader in quietly. They may be discursive.. which used to be more fashionable than now. The one thing we now find off-putting at the very beginning is a single very long paragraph and especially a complicated one which introduces several characters, or characters and places/buildings/rooms, which describes something, someone, some-place in great detail, which introduces abstract or philosophical discussion."
Not sure how Susan would characterise the following first paragraph from a novel I've just picked almost at random from my shelves. But it does the trick for me:
"I was leaning against the bar in a speakeasy in Fifty-second Street, waiting for Nora to finish her Christmas shopping, when a girl got up from the table where she had been sitting with three other people and came over to me. She was small and blonde, and whether you looked at her face or at her body in powder-blue sports clothes the result was satisfactory. 'Are you Nick Charles?' she asked."
Yes, the narrator is a MCP (in those days what guy wasn't?) but he - well, his creator - knows how to seduce the (probably male) reader. The setting is evocative and the presence of a young woman there, intriguing. The "girl" herself is both beguiling and bold. She's with "three other people". Who are they, and what does the woman want? And there's the reference to "Nora", who we (correctly) assume to be our protagonist's wife. The mention of her adds a twist to the scene's sexual chemistry: we learn that Nick Charles is spoken for, know that the woman doesn't know that yet and know that Nick thinks her attractive. And we'd quite like to know if he is capable of infidelity. So there's three sentences that earned their keep.
Which novel is it? Warning: this link is to a spoiler.