A simple planting scheme like around this stacked rock lined pond doesn't take a lot of thought to create or a lot of time and energy to take care of. With a few varieties of plants repeated around the pond and throughout the yard and garden, it's easy to fill in the space with an atmosphere you might find in a natural setting. It's when we try to add too many varieties of plants with too little knowledge that things become cluttered and unnatural.
While variety and type of plants matters in your choices, there are also other characteristics to consider when choosing the right plants. For one, being around water, you may want to consider evergreen or semi-evergreen plants that don't drop too much debri that will get caught in your pond filter and pump as well as clutter up the floor of the pool. Other considerations might include color, texture, and conditions to the specific area where you build your pond.
Since this pond is a simple construction type of a stacked rock shore surrounding a pool without a running stream, care and consideration needs to be given to the soil and ground cover that is directly against the side of the pond. Often, an incline as well as some space between the plants and rock lined shore edge will prevent too much debris from entering the pond in heavy storms.