I know this comes up fairly often but I feel like we've not had one for a while...
My top ones at present:
Cutesy/cosy phrases used about adults e.g. (spotted on MN) "why were they in the garden at 2am anyway? Surely they'd be tucked up in bed and fast asleep."
Being 'helped to' re. food/drink. e.g. "she helped herself to the last of the champagne"
"tucking in" re. food.
Tabloid favourite here "tipping the scale at".
What makes your brain itch?