To be able to read with fluency, it helps to know upon recognition the words you are reading. Eventually most words become sight words, but when students are in those early grades (K-3rd), they are still learning to sound out words and learning their first words. It helps to teach them the basic sight words from the Dolch sight word list. One list that works really well is the McGraw Hill/Macmillian list. It's sorted by "need to know" rather than alphabetically. Kids learn
This list goes all the way to 200! Quite useful. Now, on to the tip. No, that wasn't it. That was just the material to teach. The tip is when teaching them, one way to track their progress is get index cards, write the word on it and treat it like a flashcard. Store them and track them by getting a folder (like a filing cabinet folder) and use construction paper to make a pocket on each side of the folder. Make the first pocket, the one on the outside front, red. Then on the inside left, make it yellow, the inside right green and the outside back, blue. Red is for new words, not moving very fast yet. Yellow is for starting to move, starting to learn. Green is going, almost perfect. Blue is storage, just for review, you've conquered the word. Students start with their new word in the red pocket. The next day if they can say it as soon as you show it to them, move it to yellow. If not, keep it in red until they can. Let them move only 1 pocket a day so they have to prove they know it 3 times. When you start the lesson for the day, start by going over the words in red, then go over the words in yellow, etc. You can review all the blue each day or only sometimes, depending on the child's needs and ability to remember long term. Some kids take daily practice for a couple of months to really get it into long term memory. Some know it right away. After reviewing all words currently in folder, introduce the new word and put it into the red pocket. Using this method you can track exactly what words the student is learning and working on. And the student can see and track their own progress. They enjoy counting the cards in "blue" and really try to get all their words moved there!