Filling around the original root ball with potting soil. Let's look at each of these steps with a critical eye to see if improvements on transplanting techniques can be suggested. Step 1 assumes one can tell if a plant needs a re-potting based on the presence or absence of roots around the perimeter of the root ball. Plants tend to form roots around a root ball for reasons other than the pot being too small. Plants develop roots close to the pot any time oxygen starvation of the root system occurs.
Roots also develop near drainage holes and soil surface as a result of oxygen starvation.
Changing the watering practices or changing the soil mix to a looser rooting medium may be in order. It may not be necessary to increase pot size. Step 2 recommends adding drainage for the plant. In essence, the water table maintains a constant level based on the bottom of the soil mix. Adding a layer of gravel does not lower the water table, but instead raises the water table.