Hello!
The most important things have already been written, but maybe this helps a little as well:
I use to tell my students that flying IFR (especially approaches) is similar to playing music. A well trained musician must be able to play almost every piece of music from his note sheet. Which in your case is your approach plate, which therefore needs to be placed in a visible and well lit spot that is easily included in your instrument scan (preferrably not on the kneeboard!).
But even the best musician must memorise and rehearse the real difficult and time-critical parts of his score before starting to play. In our case, these are the parts of the approach that are flown close to the ground: The minimum and the first minute or so of the missed approach procedure. These are (for most approaches) the only bits that really need to be memorised, the rest can be "played from the note sheet". 200 feet above the ground is the wrong time to start wondering "was it 1381 or 1831?" and looking around the plate for the correct figure! Same with the missed approach: The first minute you will be very busy controlling/re-configuring your aircraft therefore you must be able to "play" it without looking at your sheet.
And mind you: The most difficult and potentially dangerous approaches (e.g. into mountain valleys) need to trained and regularly rehearsed on the simulator by all commercial pilots before they are allowed to fly them with the real airplane. So why not do the same? I encourage my students to fly every training mission on the PC at home the evening before our flight. It costs nothing and provides an excellent preview for the timing and the sequence of events that they can expected from the real flight thereby taking a lot of unnecessary stress away!