When choosing triangle tomato cages, it's important to select a size that is appropriate for the plants you are growing. Taller cages are ideal for indeterminate tomato varieties that continue to grow throughout the season, while shorter cages are suitable for determinate varieties that have a more compact growth habit. It's also important to choose cages made from durable materials, such as galvanized steel or heavy-duty plastic, to ensure they can withstand the weight of the plants as they grow.