When you are bossy, you are trying to control other people and the situations that you find yourself in. Other people don't enjoy the company of bossy people and often you don't like yourself for being bossy. Avoiding being bossy takes practice and self-recognition of your capacity to be a little too know-it-all.
Sit down and listen. Instead of trying to impose your worldview and thoughts onto other people, take time out from that need and just listen. What are others really saying? Is it so urgent to make them see things your way?
Start joining slowly in to conversations. Rather than asserting yourself as the person with all the answers, simply ask questions as part of your joining in the conversation. Ask about people's feelings, thoughts, wants, concerns, etc. and avoid overlaying your feelings, etc., in return.
Adopt the mantra: "People should choose for themselves". This means that you become open to presenting options and reaching compromises rather than insisting that it's "your way or the highway". Find the middle way instead and the means by which your interests and the other person's interests can meet in the middle. It might mean giving up a little of something but in turn, you'll gain a great deal more.
Be yourself. This is a cliché but it is also true. When you are trying hard to be something that you feel is expected of you rather than being the person you consider yourself to really be, it is easy to fall into bossiness to cope. Throw away those expectations that have been driven into your mind by others in your life and start living by your own values instead. Once you have those values secure, you'll feel a lot less need to push others around because you'll stop seeing others as a challenge to your identity.
Accept difference. Not everyone can do thing's at a hare's pace and not everyone is good at the things you're good at. If we were all the same, there would be no room for excelling and there would be no place for learning about diversity. Be grateful that there are differences and instead of seeing obstacles in the way others behave, look for their strengths only and work with those. This is especially important if you've fallen into a bad habit of thinking that you have no weaknesses; that sets you up for a fall. Instead, show people you know how to recognize their strengths and work with those.
Enjoy life! Bossy people don't have time to stop and smell the roses because everything must be "just so". Let it go now and then and just stop. Tame that perfectionism before it engulfs you!
People won't always go for your options. They will go for the one that is more appealing, more quality and more.