How often have you experienced that you read a difficult technical text no matter how slowly and still hardly understood anything? Consequence: You can start right back at the beginning. 

Our suggestion: Make a virtue out of necessity – and decide to read the text twice in the first place. The first time, however, read it much faster, i.e. without claiming to understand everything immediately! At twice the reading speed, the time required is identical. 

At the same time, this approach offers the following advantages:

• It is more fun! You lean back and relax the first time you read and see what's in store for you. No need to be perfect – it is enough to understand a few ideas first, to get a rough picture.
• Many incomprehensible or boring details later turn out to be of little or no importance. In trying to understand everything immediately, however, we pay far too much attention to them.
• Often, the meaning of difficult text passages is only revealed by the context in which they are embedded. In other words, a fact only becomes comprehensible when we read on. Again, when we "read once," we waste time unnecessarily "puzzling around on the spot." 
• ... and the real highlight: You will often find that you don't even have to read the text (completely) a second time – even if you read it much faster than you are used to. You will be surprised how much you have already understood and perhaps the second reading will be limited to individual passages. The deeper meaning of this exercise is that you will gain more self-confidence.

Our recommendation: When you read fast twice, apply this to rather small passages of text. Do not read several pages at a time twice quickly, but at most one page or even just one paragraph. Of course, it is also important that you have done a preview beforehand – especially so that you can better integrate the individual parts of the text into the context. 

By the way, this approach is also useful when reading foreign-language texts if you are still somewhat "unfamiliar" with the language. In this case, it is especially important that you first ignore unfamiliar vocabulary and learn it from the context. (If necessary, you can already look up frequently occurring new words after the preview).

By the way: You will save a lot of time if you leave the pen aside while reading and do not mark anything yet. Only when you read a second time will you know what is really important and can highlight less accordingly. On top of that, the pen slows down your reading speed and tempts you to subvocalize 100%.