There are some good suggestions in the above posts. Here are my methods, for what it's worth.
I've found it useful to review the approach (if possible) before the flight and highlight critical information with a fluorescent pen. As you progress in your career you will 'blindly' find the right bits.
In flight, after briefing the approach I note down the following sequence of critical information (actual values for the IAP go on the lines - I think all are self-explanatory; 'Alt' refers to the intercept altitude for the procedure):
IAP/RWY_______ Freq______ CRS_____ Alt______ (M)DA______ MAP__________
Depending on your aircraft equipment, tune the required navaids and dial in as much info as you can on OBS, altitude tapes etc.
During the approach, constantly ask yourself what should be your current track & altitude, until when and what is your next track & altitude.
Good luck!