First, I'd like to point out that you can't really become a Dominant. Being Dominant is a characteristic you either have or you don't. You need to look inside yourself and figure out whether you have a natural desire to control, tie up or otherwise dominate a partner (sexual or otherwise). This is something that no-one but you can decide. Is this a need or desire for you, or do you want to do it to fulfil someone else's fantasy?
Of course, I am loath to dissuade anyone from sexual experimentation and kinky activities, as these can be invaluable in teaching you more about what you and your partner likes in terms of bedroom role-play. Even if you're unsure about your orientation, that's OK. Keep experimenting and enjoying finding out more about who you are!
If you know that Dominance is a life calling for you, simply keep in mind the top three priorities: consent, safety and fun. After those, it all comes down to the personal preferences of you and your chosen submissive or partner, so enjoy the learning process.
Also, don't be afraid to connect with the larger BDSM community either through the Internet or in your local area. Ask other Dominant men and women for technical tips for practical purposes, such as bondage, CBT, chastity, verbal humiliation and more. You can of course find in-depth advice on specific fetish and BDSM activities through researched and expert articles online as well.
So, the short answer to your question? If you're a Dominant, that's what you are. You can become a better master through continued learning, an open mind, and experimentation.