Soon after emerging from the editing cave, blinking in the light, came two realizations: I would need to do some publicity, and I needed a new author photo.

It’s like that advert about changing your mattress regularly every eight years, when it dawns on you that the last time was a bit longer ago than you imagined.

No, the FotoMat won’t do (not that kind of FotoMat, anyway). It’s strictly for driving licences, passports, and the FBI wanted list.

Neither will a selfie taken holding one of your own books and grinning maniacally. And definitely not the charming efforts taken with best mates in a giggly stupor.

My husband declined to volunteer his skills. I didn’t need high-res images of thumbs. I needed a professional. Enter the brilliant Mat Smith Photography. 

Two hours with Mat and his assistant Anna taught me a lot. I have yet to study the results, but this I know:

1 There is such a thing as too much sunlight. Who the hell wears sunnies in an author photo?

2 Have lots of outfits to change into, but don’t use your entire wardrobe. Every single garment you choose for the photoshoot has to earn its keep.  No massive flowers, busy patterns, or shouty diagonal stripes. Consider the image you want to project (friendly, intellectual, offbeat?). Think too about the outfit in its own right. Or, as Mat and Anna would have it, “What does it SAY?” This is the best question I’ve ever heard about clothes, and I plan to take it with me every time I go shopping.

3 Avoid too many props. You don’t need to wear a stethoscope to convince people you’re a medic.

4 Smile. It’s your natural face-lift. I base this advice on the fact that I look decades older if I keep a straight face. 

5 Look into the camera rather than the distant horizon. It will make you look interested rather than aloof. Yes, this applies even if you have one dropping eyelid (most people do).

6 If you pose in the street, people will wonder whether you’re a celeb. It’s neat to have some publicity material to hand them, even if it’s from your last book.