Okay, I only have one child, but I always seem to lose it in our local supermarket. There is something about that place that just gets to me. I usually try and do my big weekly shop alone, but when I run out of something I have to go in and it usually ends in me losing it.
We watch this TV show called 'Poko' and they have this little chant they say when the boy is upset and angry. It goes
'Hug a monkey'
hug him tight'
Hug him till you feel alright'
(The boy has a toy monkey, thought I would just mention that)

I imagine he is my monkey and I hug him while saying it. It makes him giggle and it makes me feel better for some reason.