For your typical instrument flight planning, to reduce in-flight cockpit workload, how many IAP plates do you study and in what level of detail? There can be a lot of detail on every plate, but there are similarities. If there are four plates per runway, and multiple runways, it seems impractical to memorise all the detail on every plate.

I generally expect radar vectors to the ILS and hence will read the ILS plate into much more detail. For the others I'm told they're generally used for backup & training and hence would tend to read a bit less and just write down the calculated DA/MDA. Is this a good or flawed strategy?

Have you been faced with having to study a new plate while still hand flying it in cloud (e.g. winds changed, and ILS + radar failed)?

Sadly I do not have the luxury of an autopilot...

I would be inclined to get comfortable with the plates generally (assuming you are not). When you have a moment in the office or where ever pull and plate and run through the procedure. You will quickly get to the point where you can fly most plates having pulled the relevant plate in the cockpit as required. This means if there is some totally unexpected change in plan you are comfortable re-organising your plan.

Beyond that personally I wll have a look at the approach I expect to fly (which will always be vectors to the ILS by preference) and I will also have a look at the hold just in case I am put into a "procedural" approach. I will do the same for my diversion. That is about it.

I agree - an autopilot is a huge help. Should the need arise to find an unexpected plate while flying the aircraft and self briefing the work load is always going to be exceptionally high - some might argue too high.

You should have a read of the plates before flying, just to make sure you understand everything on them.

Most of the stuff is obvious but sometimes you get things which need attention. For example some departures (SIDs) have minimum climb gradients due to terrain, and you need to be sure you can fly those while achieving adequate engine thermal management.

Another example might be a little note saying the procedure is not available unless x,y,z. Example: Biggin procedural approaches are not available (last time I checked) unless Thames Radar is out of action (presumably because Biggin pays TR £xxxxx/year for the service and they want to get value for the money ;) ). I recall Oxford has a similar deal with Brize; I once asked for an approach and they would not let me have it.... then I spotted the little note.

Otherwise, you should be able to correctly fly any plate which somebody sticks under your nose, minutes before arrival :)

Fortunately it's not hard; if this stuff needed a PhD then 99% of the world's jet transports would end up in terrain, and currently only the African ones do that quite often ;)