Have you ever started to read a book in English and find yourself stopping every time you find a new word, then you look it up in the dictionary and continue on and then you start highlighting expressions you don't understand?.... Well by the time you have finished reading that paragraph, you feel that you didn't really understand it, so you read it again and again. Well, guess what? You are doing it all wrong and after a while of doing it this way most likely you will get frustrated and quit reading all together.
Reading is a habit and it is a fact that it does help your fluency, connecting ideas and enriches your vocabulary. I will show a technique that will help you read fast and understand in a most effective way. The technique is called SKIM vs SCAN.
SKIM: For this you must start reading fast from top to bottom without stopping. The idea is to get the gist or main idea. When you start reading an article you may also get some information about the main idea in the title, maybe an image or the introduction. If you find a new word or expression and you stop every time you will get unfocused and will never be able to get the main idea. You must get used to understand by context or comparison. It is not necessary for you to understand 100% of what you read; meaning every single word.
SCAN: During the scan you will read for the second time, but this time only looking for specific information or detailed information. Similar to a scanning machine except that with your eyes just searching for actual facts.
You will find that if you practice this technique it will improve your speed as far as reading is concerned and your comprehension will also get much better.
A quick tip about understanding by context is when you find a word or expression you don't understand or don't know the meaning of it, it's a good idea to always read before and after that word or expression to understand the message.
As I mentioned before, reading is such a positive habit, therapeutic and if you start enjoying it not only will your fluency get better but also your choice of words.