Pressing too fast or not pre-pressing for long enough are just a few of the most common mistakes made by beginner extractors. The thing is, these variables can't be generalized and set, because they may change from grower to grower, or even crop to crop. The trichome heads may act differently and the standard operating procedures that worked before, might not work so well now. An example of this is when a strain that you have worked with before starts caking out on the press at the same temperature where it was flowing beautifully before from past crops.
Be willing to learn on every new press you do and to adjust when necessary. Be mindful and feel (if you have a hand press) how quick the oil is able to come off the plate. Your goal is to get the oil off the plate is fast as possible without a blowout.