Lo-tech Watering Can

As a way to save water dollars, we've begun to collect the cold water that would otherwise run down the drain when we shower or bathe, into a pail, which I use for watering the garden by hand.
I made a free watering can from a half-gallon milk carton. I used one from Promised Land dairies, because we had some and they have the nice molded hand-holds on the back of the carton. I nail-punched a circle of holes, with a center one, as well, in the screw-on cap and cut a small slit at the top of the back for air exchange.
It works quite well, for what it is.
To improve, I would use a smaller nail and more holes in the cap and make the air exchange slit much smaller, as well.
When we use up the current milk carton, I'll try that out. I need several, as all the kids will want one.