I've gone around the house and measured everything possible. Some things I measured over several hours to a day (like the coffee machine, fridge, laptop etc). Others seem to draw fairly constant power, in which case I just measure for a few minutes and multiply by time on.
Got a few surprises - such as the heater for the fish tank. (The fish are now gradually getting used to a slightly lower temperature. Everyone has to do their bit.

) Another more pleasant surprise was that the fridge doesn't draw as much power as I thought it would - nor as much as is indicated on the fridge label.
I'm just using a cheap $30 meter. I'm not worried about absolute accuracy. If something seemed off I'd check it against whatever it says it's rated at - but that hasn't happened yet.
Should have done this years ago!