While photographing nature the brand of your camera hardly matters. But, what matters is your sense of understanding, fixing on the object and light. For nature photography the best time is early morning and evening. During this time you would not get ample light, hence your understanding is crucial. Try using a tripod, it makes your photographs look sharper and allows you to capitalize on the less exposure time during lesser light. You should also take several shots of the same object, trying out different angles. It brings a depth to your skill and opens up more options. Another important aspect of nature photography is moving closer to the object. Focus on it and move as close as possible.
Other valuable practices that enriches your nature photography skills would be taking a lot of photos, reading books, trying out creative shots, taking notes and definitely enjoying what you. Make sure that you travel a lot. This gives you more opportunities to click and learn. Browsing through different pictures also helps you gain knowledge.
Photography remains an art that can be self-taught. Hence if you have the correct enthusiasm and a passion to learn, you definitely have a lot to prove.