My best piece of advice is summarized in 3 phrases.
Think big. Act small. Master your craft.
If you want to start your own business, you need to THINK BIG so you can see the entire picture. That also means you need to study the industry and look for opportunities or possible niches that you can specialize in. Some entrepreneurs fall victims of the usual start-your-own-business seminars where they teach you how to produce a product like soap, candles, or any other simple items, and convince you that you don't need a big capital for that. Then, you realize in the end that what matters most is the marketing side of the business amidst the strong competition. Then, you end up not being able to sell anything. The reason is that those seminars are think-small and easy-to-start ideas. Always THINK BIG by studying about the unmet needs of the market, about the bigger picture in the industry, and what is required to compete.
After seeing the big picture, you might be overwhelmed by the vastness of the industry and the amount of work or capital needed to start your venture. That overwhelming feeling may not inspire you and may push you to procrastinate. To overcome this, you need to ACT SMALL. Segment the market into smaller pieces, find a niche, do something in small scale, and start immediately. After all, you already know about the bigger picture and you know where your small act will end if it will succeed. By acting small, you can break the inertia and build a momentum. By acting small, you will also need less capital, time, and effort to start the venture.
The next thing you need to do is MASTER YOUR CRAFT. Since you started small and with focus, you can afford to master your niche and do better than competition. Slowly gain momentum and expand your scale.
In my 15 years as an entrepreneur with several ventures, I learned about these 3 simple steps to get my ideas running once they hit the ground.