Break all your tasks down into small bits. If you're setting up for a procedure don't get your head down and do everything, only to look up and find yourself 150ft high and 5 degrees off heading.
Check you have the correct plate, fly the aeroplane, tune in your first frequency, fly the aeroplane, verify the frequency, fly the aeroplane, set up your inbound course, fly the aeroplane etc etc
I was taught very early on to learn to fly with one hand, if you can use just one hand to turn onto new headings, roll out, maintain altitude then you free up your other hand (which is normally holding a pen/pencil) to scribble clearances down, tune radios, grab airways charts etc, and if you can do that while maintaining a rate 1 it can help you stay "ahead of the aeroplane".
The IR is all about cockpit management.