I know this is common sense, in case you are not doing so yet, you can start today! 
I remembered one “Save Water” advertisement once have this catchy phrase “Bathe with a friend”. This tip here is “Cook with a friendly food”.
If you are cooking one meat/vegetable on the saucepan, there’s still space in the saucepan, fill up the space and cook another meat/vegetable. Do it for food that will not interfere with the taste. So you cook 2 dishes at the same time, save you time and gas (rather than doing so separately).
Yesterday, while frying one fish, I shared the saucepan space and cooked 2 other vegetable dishes (cabbage and bean sprouts).
