To be a great entrepreneur the first thing you must be able to sell is yourself, it is one factor that determines the doors that will open for you and how far you go as an entrepreneur. This means that if you can't sell yourself you won't be able to sell anything as an entrepreneur. While some are born with the gift of being able to sell there's no rule that says you can't learn to sell yourself as an entrepreneur. Your words as an entrepreneur should carry weight , exude confidence and resonate success whenever you sell yourself. It is a psychological advantage because being confident and able to show the world what an excellent person you are goes a long way in affecting the way you see yourself as well as the world. It becomes a great habit you can't break from and this is a key ingredient to being successful.
But to sell yourself first you have to become sellable, you have to improve yourself as a brand. If you have been dressing like a slob that needs to change, if you have been eating like a slob, talking and walking like a slob all that needs to change. Make deliberate efforts to change the way you talk, walk and dress, rather than living off pizza and burgers which affect your physique as well as your health and mind start eating healthy. Let your closet consist mainly of more formal, elegant and confidence exuding clothes because of course you will be addressed the way you are dressed. Take speaking classes to help you talk better and more confidently in public. This doesn't mean you become prideful or obnoxious but rather enough confidence to move people to trust and buy what you are selling be it a product or an idea. If people don't feel you can be trusted they won't buy you much less what you intend to sell.
Next you need to know your target audience and target them. You can have the best idea or product and be well articulated and all but if they are targeted at the wrong audience you would just be barking at the wrong tree. You have to find the right audience, if you intend to sell a cosmetic idea you don't go to an information company or social media company but rather a cosmetic company that will be willing to hear and buy this idea. Make you research about what your ideal clients want at the moment and how your idea could help them because unless you are solving a problem in the industry people won't listen to you. You could also spend time with them by going on conferences, functions where people like that happen to gather so they can warm up to you and help them trust you even better. This will also help you in drafting a better selling technique or even a better business idea that most companies would kill for.
Ultimately make sure that whatever field you are as an entrepreneur you are an expert at it because you can only give what you have. If people can sense that you aren't that good or you don't have a firm grasp of the industry they won't listen to you much less buy you. Go for trainings, learn from experienced people and invest in yourself because you are your best salesman.