Our house rule is new tools only on Father's Day.
I sit with the kids (2 girls under 8yrs) in the weeks leading up to the big day, we go through all the catalogues and I explain what the specific tools do and what I could make if they gave me one.
If money is a bit tight they get me small things. A couple of years ago I got a shifter and a pair of vice grips.
And when I have big projects to do I get lots of tools.
Last year it was a full 18v cordless kit (drill, driver, grinder, blower, 3x 5ah batteries).
The wife takes the girls in and they tell the salesman EXACTLY what I need.
Apparently the salesman tried to convince them that the Blue Bosch kit was better value, but there was no way they where leaving without the green Hitachi ones we had been looking at and they had decided where the right ones for me.
This year was supposed to be a chainsaw, but I couldn't wait and already bought one....
So looking at the next trailer project I'm about to start on, I'm thinking there might be a new pedestal drill or tube bender on the way soon.