If you want to prove yourself as an artist, first of all, you will need to find your own signature art style. That is the best way how you can represent yourself and your art. This is an absolute necessity if you really want your art to become known to the people who are looking to buy. Developing your own style is as important as having an original idea about what you want to do and how you want to artistically express yourself. Your own distinctive style will help you a lot to get through to people and they will acknowledge you more if you develop your own style.
First of all, a style comes completely deliberately to you, on its own. It takes some time to get clearly in your head what you really want but, once it comes to you, keep it. Your style is just an element of your artistic process, a means to amend.
Be open to all ideas because what you do not like today, you will maybe, tomorrow.
Do not take too much time to build your style. You could do it in a week for sure. Just like you build your own character, you have to do the same with your style. Always put some serious thought into your choices. This will be something like a foundation for your own personal signature artistic style. It is quite a creative endeavor, to be honest. If you know the definition of creativity, it should not be too hard for you to create your own signature.
So, to do this properly, you need to take some steps. Identify an art style that emotionally resonates with you or pick an artist or a few that you really like and are an inspiration to you. If you could choose an image that represents you and your choices in the best way, do it. Analyze that image. Three most important questions to do this are what, why and how. These will give you answers to all your questions. Finally, put all of this gallantly together.