I never read the Michael de la Maza book, but when starting with chess I read his ChessCafe.com articles "400 points in 400 days".
His concept of the 7 circles of tactics exercises are famous in the chess improvement blog sphere, and I have done my share of Chessimo exercises inspired by his article.
There is however another aspect of his training that has not received the same attention. The micro-level drills, where he trains his chess vision to instantly see things like knight moves, forks and skewers. This is the part of his method that resounded most strongly with me, and I believe his personal improvement would not have been as fast or as great without it. Whenever I find a part of my chess thinking that is a lot of effort, while it really should be automatic, I try to formulate a drill to fix it. In the past this has involved material counting. Arithmetic like "3 - 5 + 9 - 5" to assess how an involved exchange affects material balance should not require a immense conscious effort.
Lately I have done a lot of mate-in-one exercises. In a game yesterday I discovered that I am prone to overlook knight moves, and spend disproportionate amounts of time when calculating knight maneuvers. Quickly spotting weak squares is another upcoming subject.
The point is to quickly and automatically see what should be obvious, and to save the conscious effort for calculation and finding candidate moves.