Things that should be remembered, but are aggrivating when they aren't.
Eggs
Older eggs separate to yolks and whites better than newer eggs.
Eggs separate more easily when cold.
Whipping
Egg whites should be room temperature for the best whipping results.
Whipping cream should be very cold for the best whipping results.
Whipping cream will sweat and slip around after a few hours unless you add 1 tablespoon of skim milk powder for each 1 cup of whipping cream while whipping.
Milk
Any recipe in my collection that just says "milk" means skim milk from cows - it's the milk I always have in the refrigerator. These recipes may work with other types of milk, but I can't guarantee it. When a recipe specifies another type of milk it means I have not tried it with skim milk yet.
Oops! I forgot that...
Sugar - when you forget to add the sugar in the muffin recipe the muffins will be very oily and not really worth eating
Best Tips
The best website I've found for cooking and baking tips is: OChef