You will need:
A blow pipe
Piriton-tipped blow darts
Scaffolding and pincer clamps to hold your little precious in place
Make up to paint realistic looking eyes on their comatose lids
But if, for some reason, you don’t want to violate the UN Convention on the Human Rights of the Child (though the Government seems just fine with it) then here are a few other tips that might help.
Sleeping: The best photos of kids are when they are sleeping, by which I mean, still and silent. It’s probably the time we love them most - when they’re not actually doing stuff. If you find an instagram account full of images of an angelic cherub in quiet repose with a mum who is #soblessed you can guarantee that child is an absolute horror when conscious.
That is the same child in both photos, I swear.
Seasons: Think carefully about when you are going to photograph your children. Always bear in mind that children are disgusting - in summer they’re constantly covered in ice cream, in winter it’s snot. Only take photographs of children in spring or autumn; for a start, the light is better and it also gives them something to do to ensure they all stay in frame. During spring you can just about corral a group of kids into something approximating a cute action shot by getting them to chuck blossom in the air. You can do the same with fallen leaves in autumn. Bear in mind you are guaranteed that the most sensitive child in the group will be treated to a very surprised slug clinging onto them for dear life after its first airborne experience. In my experience it only takes about 4 hours for the crying to stop.
Jumping: I have a friend who manages to get perfect images of her and her kids star jumping in various beautiful locations - truly gorgeous photos every time. Having said that ,she’s also a size 6 after having 2 kids so I think she may be a witch. When I try the jumping thing it never works - small kid’s hair has its own gravitational field and she frequently ends up looking like Cousin It and big kid seems congenitally incapable of not dabbing when engaging in even the slightest movement. You need a really really good camera for jumping shots to work and for your kids to have a basic understanding of timing so they actually jump in unison on the count of three. We do not have ether of these things.
Sculpture: Having your kids pose in front of sculptures feels like a double win - good location and a short cut to showing how cultured you and your brood are. The problem is a lot of modern sculpture look remarkably like climbing frames, especially through the eyes of a four year old, so your artsy shot is likely to be spoiled by judgemental mutterings from the tweed clad national trust brigade and your own frantic hissing “to just stop behaving like bloody monkeys every time you see a plinth”. That level of tension seeps into the finished photograph every time. Trust me.
Lavender: I do actually recommend taking photos in the lavender fields - everyone looks good in with a pale purple backdrop and I’m sure that lovely scent has some sort of calming influence. It just depends on how willing you are to organise a day trip and drop a bunch of cash just to get some nice photos. We did it when the kids were 5 and 2 respectively and swore we would be back every year to mark the passing of time in an artistic, elegiac way. We did it once.
Children kissing: We’ve all seen them - those lovely sepia tinted photos of two tiny children sharing a gentle but heartfelt kiss. Adorable. In reality you are lucky if they escape with only a minor concussion. There are also some tricky ethical issues to contend with: the intricacies of discussing consent with the under fives is hard enough - directing them to kiss against their will is sending mixed messages at the very least.
Never use props: The idea of novelty photos is a cute one - everyone dressed to mark a seasonal celebration or all the family following some whimsical theme like the Algonquin Round Table so they look quirky and artistic seems like a good idea on paper but in reality at least one child (or adult) will vehemently resist the application of any form of costume (see below - small kid should be wearing the mask, not big man) and another one will take the theme so far they are rendered unrecognisable. And don't get me started on what happens when you put a herd of children into costumes at the same time; suffice it to say the next photo you take will be of a super large measure of your favourite tipple.
In fairness to all the small humans out there it's not like us adults give our best performances in front of the camera either