Manually copying information that is available in the required publications is mostly a waste of time, unless you're scribbling a quick note about something unusual. The information is already written down for you - that's why we have those documents in the 1st place. You just have to be able to know where to look.
Like others have written, you need to be able to discriminate between essential planning & preflight information & activities, and non-essential stuff. Also, how efficient is your flight planning & preparation process? Do you waste time going back & forth trying to complete tasks? Can you shave time during planning eg plot all the tracks, then measure all track bearings, then measure all the distances etc instead of dealing with each leg individually. Is your equipment organised in a way that lets find the bits & pieces easily. I find it helps if I keep each item in its own place every time. I don't have to rummage here & there to find things.
Once you have a planning routine that captures all the essentials quickly & efficiently your flight planning will be much quicker.