Having confidence in yourself as a real estate agent means you are less likely to give up. In the real estate game, competition is fierce and if you give up, you let them win. As a real estate professional, you need to be passionate about what they're doing, which I've discussed before, and that passion will drive you to insist on nothing but success.
Despite my saying you need confidence and the ability to fight for what it is you want, you do need to be aware of your weaknesses. You should know yourself better than anyone, so know what your strengths are, and know where you need to do some work. If you're fully au fait with how fabulous your real estate skills are, you'll be much better versed to relay that to the person who could possibly be your next client.
Use your personality – building your own brand based on you can only be about who you are. In marketing speak, your personality is your unique selling proposition. There's only one of you, and if you're a committed real estate professional, putting your personality out there is what's going to start building your reputation and personal brand.
Another marketing rule that translates to building yourself as a brand is to be consistent. Brands are built on consistency – you don't see McDonalds changing the colour of its arches on business cards or the website, so you shouldn't either. If you're consistently making your customers happy, word of mouth will get out there to help build your personal brand faster. If you want people to know who you are, you need to make sure what they know are the right things!