#1 Choose your paddle according to your level
If you are a beginner, it is best to go for an aluminum paddle for its strength, because it is not uncommon to fall on your paddle or press down hard on it when starting out. Another advantage of aluminum is its affordable price.
If you are a regular touring paddler, you will be looking for a more lightweight paddle that you can use for longer periods. Carbon + fiberglass models save a good amount of weight and the blades remain easy to use (they steer well like aluminum paddle blades but do not require a great technique to control them).
100% carbon paddles are even lighter, more fragile (they must be protected from impact, a carry bag is recommended) but also more technical because the blade is designed to give more power at the expense of comfort and stability in the paddling movement.