Dopey question about freezing ice cube tray portions: do you have an ice cube tray with some kind of lid? Or do you just have it open in freezer? Seems kind of gross but that might say more about the state of my freezer than I care to admit.... I don't want to buy any more Baby Stuff unless it's genuinely necessary, just wondering if people use regular trays some mums may be doing it right so many are going to far and it's getting way out of handor something else!