Another thing I have noticed is that size matters. For the various degrees of done there is a small window of time at each temperature. I have found that always using the same size egg matters especially when making soft eggs. I like using medium for soft ones. Ember is correct that you want the freshest eggs possible. This is where a notebook comes in handy. Once you have a process perfected I suggest documenting it in your notebook so it is easily repeated down the line.