Focus and taking in information when reading

This is an odd problem but I wanted to post here to see if anyone else experiences this and has any work arounds.  I really struggle to take information from reading documents.  I will start reading it, but mind just wanders, especially if it is something that is not particularly stimulating.

I am adult with A levels and a degree, so I clearly managed to get through the learning process before.  What I used to do was write bullet points from a document as I was going through it (with each bullet point written in a different colour as I found that used to help me when trying to commit the bullet to memory).

I am wondering whether I need to go back to doing that - but that makes life when reading papers or documents at work rather cumbersome.  

Has anyone got any tips to help stay focused when reading documents, and more importantly, any tips to help try and retain the information that I am reading?