If batter is too thick, thin out with a bit more milk.
These waffles took about 4 minutes to cook ½ cup batter in each slot of my Breville Waffle Maker (using custom setting), which is less than my original recipe. Once waffles stop steaming (or almost), they're most likely done. Should be golden brown in colour.
To freeze, cool completely, then store in an airtight container with a bit of parchment or waxed paper between the layers.