Diagramming on CR questions

This is what worked for me. However, it only came through sustained, intense practice. Eventually, you become conditioned to be actively thinking while reading the passage - which for me works better than diagramming.

I always read the question first, identify the question type and write myself a reminder of the question type on my verbal answer grid.
For example if the questions reads something like: ..... strenghtens the .....
I'll put a 'S' down for weaken or not strengthen a 'W' and inference question 'I' Evaluate Argument 'EA' etc. where applicable I also did that for RC.
Then I read the argument. Then re-read the question. If possible pre-formulate the answer and then go through the choices in order, eliminating one by one. When I go through the answer choices I use my own system, if an answer does not fit I put a '/' on my grid, if it's a maybe '?', and if I think it is the right choice 'o'. For the sake of argument let's say I put 'o' for B I still go and look at the other choices. I also use combinations of those symbols, for example I'll get to choice D and I might put down '?o'. I will then go through the answer I think could be write and use POE. Sometimes I end up with three answers '?' which then tells me I do not have a good handle of the question and I reread the question, then the answers and if needed the argument.
This approach worked for me, but I have not seen any 'authority' really promote this course of action