I dont think there is a method, just play more HD and improve your NM acc. I used to attempt HD on and off for a while, not very often, and after my NM skill improved to a certain point, I had a jump in HD skill, enough to find the mod fun rather than frustrating
Start with maps that have easy bpm and sv -- farm maps with simple patterns, etc. that you can comfortably play NM. Most efficient way to get used to reading HD is on stuff where you can focus solely on the HD aspect, and not have to worry about anything else.
When you're playing HD, don't overthink, just try to play like you do normally and trust your instincts, have faith in your rhythm sense. It might be hard to blink at first and you'll get dry eyes lol but that goes away with time