A low flow toilet can easily become clogged by adding too much paper when you flush. The amount of pressure on the flushing of a low flow toilet is far less than for a higher flush, and therefore is more prone to drainage problems.
Step 1 - Preparing
Place plenty of old rags or towels around the base of the toilet bowl. You might create some overflow as you plunge, and water can run over the top of the bowl before the clog is cleared.
Step 2 - Gloves
Put the gloves on. Gloves are an obvious accessory when dealing with a toilet problem, and they will also give you extra grip on the plunger.
Step 3 - Plunge
Place the bell end of the plunger into the toilet bowl slowly, to prevent splash back. Set the plunger so that there is no gap for water to come out of the U-bend hole and press down firmly. The up stroke is more important than the down stroke, because you need to create a vacuum. Pull the plunger up fast and press down again and repeat. Do this at least 4 times, and then check to see if the water is receding.
Step 4 - Checking
If the water begins to return to normal, flush the toilet. If you see no sign of it receding, do not flush until the water level has returned to normal.