Having established in an earlier post the central importance of sight-reading in the training of the musician, what concrete steps might we take, and with what resources, to improve our skills? First of all, and most significant, is regularity of practice. In order to improve, we must practise our sight-reading daily, and with a plan not merely to do "the thing and get it over with" but always to advance. It is no good simply to choose some ABRSM exam exercise and play it once. This will help a little, but it will be ultimately ineffective.
Use quick studies to help your sight-reading get better
By quick study, I mean simply a stand-alone piece that is just slightly below your normal playing level. In particular, we would want to avoid pieces involving technical demands that we would struggle to play, even if it is not difficult to read the music itself. For beginners, since it is nearly Christmas, I would recommend The Easiest Tune Book of Christmas Carols, Book 1.
This book offers a number of simple pieces for the beginner pianist to learn, and are excellent for practising sight-reading skills. I would suggest selecting one piece of music from this book each week.
Once a piece has been chosen, note down all the details you can in one go. This should include the time signature, key signature, any performance directions.
Next, look through the score and note all the hand positions and the changes; try to visualize how you will play these passages as you examine them.
Then, when you have prepared your hands at the piano, try to play it through from the beginning hands-together. Do not look at your fingers. Depending on your experience with sight-reading this may go well or badly; it does not matter at this stage. Listen carefully to your own playing so that you will be in a position to judge afterwards.
Once you have played it through for the first time, go back and practise each hand independently. Try out all of the changes in hand position. After each hand has been learned, go back and play it hands together again. Rinse and repeat.
Use short, single-handed passages to develop a better musical memory
Developing a strong memory for written scores is another useful way to improve our sight-reading. If we can look at a short passage and play it straight-away from memory, the time it takes to master more complex works will be invariably reduced. Practising this is fairly straightforward: find simply lines for the right-hand and the left-hand, and, after spending a little time studying the notes attempt to play them through whilst keeping your eyes closed. Begin with very simple passages, the sort that might be found in tutor books, and then proceed to gradually longer and more complex patterns. In not too long-a-time, you will see the benefit of this practising technique.
Practise tapping rhythms in both hands
Tapping rhythms is another important way to improve our comprehension of complex music and our sight-reading in general. It is not only parsing notes and phrases that trips people up, but rhythms including dotted rhythms (dotted crotchet + quaver, or even dotted quaver + semiquaver), syncopation (where the rhythmic patterns of the treble and bass are not aligned), polyrhythms, and so on. Our practice routine is incomplete if we do not include this element of music.
They key to this kind of practise is to practise not only playing the case studies mentioned above, but also to tap the rhythms of each hand, separately at first and then together. Much like basic not recognition, if we cannot visualise and understand the rhythms of a piece of music we cannot play it. And, the better we can understand the rhythmic patterns present in a score before we begin playing, the better we will do.