If "blindfold work" means closing ones eyes and analyzing, I can't say that I've noticed a difference.
A helpful approach to improving analytical skills is to do a lot of it while keeping in mind some need to order it logically and not, for example, to bounce back and forth between candidate moves a la Kotov.
A good strong visualization is important. This may just improve with practice.
I think de la Maza's idea was to work on just that skill?
I just read an interview of a prominent Chess player who believes that that the best way to improve analytical skills is via "blindfold work". Has anyone tried this technique? If so, was it successful for you?
Do you use another technique with noted results?