Hah - re. 5, 10, 15 degrees of drift - I had 46kt straight across the hold during my test... 15kt on the ground is perfectly ok for a test. You might need a bit more drift than 15 up top!!
Think simple. Aviate, Navigate, Communicate. In your climb, your cruise, everywhere - is the aircraft trimmed and in the correct configuration, is what I want the aircraft to be doing the same as what it is actually doing? Then, are my navaids set, ident correctly and am I flying in the right direction - how long until I get to the next event? Then... do I need to talk to or listen to anybody at the moment, and who will I need to talk to or listen to next? Not very different to VFR, but it helps when you need to turn overhead a fix, descend a long way in a short distance due to ATC keeping you high, intercept an NDB track and re-plan your hold entry because the wind is veering and backing like a drunk snowboarder, all at the same time!
When you get your ATIS for the destination, think 4 things in cycle: 1. Set destination QNH on your standby altimeter, 2. Check you have the correct approach plate, 3. Check visibility against minima (approach ban?), 4. Check crosswind component for your aircraft. After this you can assess whether you are LIKELY to get in based on cloud cover, but the 4-step cycle covers the LEGAL requirements for making the approach.
Leaving controlled airspace think 2 things:
1. Which frequency for a LARS, 2. Which (quadrantal) flight level is appropriate?
Note DME distances from aids to the edge of controlled airspace during the planning phase.
Icing awareness - doesn't matter how cold the freezer is, you won't make ice cubes if there's no water in the tray! But in cloud and visible moisture check OAT every 1000'.
Most of all, enjoy it, relax, and be confident - confidence is a very important factor in performance during the IR (in my experience).
AD