To begin, take time to review the specific technical document you're trying to decipher. While reading strategies can help you to access and remember some of the main ideas of any text, it's important to be sure you have the required background knowledge for the task. If you're not an electrician or engineer, for example, a reading strategy may not provide you with enough tools to understand a complex schematic. If possible, begin reviewing the document by reading the table of contents. If the majority of the terms referenced in the headings of the text are unfamiliar to you, you may need to gain some more background knowledge before moving forward.
Once you've established that the document is at your level of comprehension, take some time to review the format of the text. Check to see if there is a table of contents, introduction or executive summary. These sections will give you clues about where you can find the specific pieces of information you need. Review the end of the text as well for the glossary or index. Both can prove to be invaluable when you need to define unfamiliar terms or locate a specific topic.
Now that you're comfortable with the layout of the document, refer to the portions that interest you most. It's not necessary to read each word at this point, but to simply look at the section headings and quickly skim any introductory sentences, diagrams or pictures in each section. This will help you understand what to expect when you begin to read in more detail and will give you an idea of what information is located in each part of the text.
Read the text through one time at a quick pace. According to the Computer Science Department at Bucknell University, it's not necessary to understand every detail in the beginning. It's important to reach the end of the document in order to reach the author's conclusions and to have a general understanding of the position and content of the text.
As you begin to actually read through each relevant section more slowly the second time, take the time to notate information that you think is important or that you do not understand. If possible, highlighting, underlining and writing in the margins are great ways to flag certain ideas for review or further study. Such notations can also serve as a valuable resource when rereading the document, eliminating the need to review each individual word. Reviewing these notes regularly will also aid in better long-term comprehension of the subject matter.