Pitching an idea to one of the worlds’ largest companies -- such as Coca-Cola, Kraft, General Motors or Apple -- isn’t as daunting of a task as you may think. Big ideas deserve to be seen by big companies.

But if you’re only one person or a small startup, you may be thinking, “How do I attract their attention? What can I do to get them to listen to me?” Most entrepreneurs think, “If I only had a contact….” But in reality, that isn’t the only way to get the door open and the conversation going. Here are six others.

Related: The 10 Must-Have Ingredients for a Successful Invention

1. Call the company. Pretty straightforward, huh? There’s a reason this step is listed first. Determine what department is most appropriate. Purchasing is a good bet, if your product is ready to sell. If you have an idea, I’d recommend product development, marketing or sales. Be professional and direct. Start by stating your name, your company and the purpose of your call. It can help to find the name of an employee on LinkedIn who works in the department you’re calling.

2. Call the company’s advertising agency. All big companies work with ad agencies. It’s easy to get in touch with people who work in advertising, because they pick up their phones. They’re always selling! And they are obligated to show their clients opportunities for new innovations. Most ad agencies brag about who their clients are, so you shouldn’t have trouble finding that information online. This strategy has worked for me before. An agency set up a meeting with one of their clients after I showed them my idea. It’s a great way to get right to the top of a company. Because the ad agency set up the meeting, it’s like they’ve already endorsed you.

3. Make the most of social sites for businesses such as LinkedIn. Choose wisely how you use these sites (don’t bombard anyone or make demands). After all -- connecting with people is what these sites are all about. There may be fees to use premium services.

Related: Give Your Ideas a Fighting Chance With These 5 Actions

4. Reach out to packaging and design firms. Many companies hire outside industrial and package design firms. They’re looking for new innovations to show their clients, too. This method has also worked for me in the past. I presented my technology to a package design firm and they passed it on to their client, who in turn called me. This strategy works better for some ideas than others, of course (notably, packaging and design ideas).

5. Start local. I was able to convince a local retailer to start selling a few of my products casually at the front of his store. When they did well, the manager of the local store called his regional sales manager to let him know -- who then presented my products to their corporate buyers. My product went regional and then national!

6. Go to trade shows and corporate seminars. Making the decision to commit to going to industry trade shows has opened a lot of doors for me, in part because of the sheer volume of my peers there. There will be tons of marketing and sales people on hand. Corporate seminars are expensive, but they offer the opportunity to meet decision-makers one on one. That’s valuable. But you can’t just simply attend -- you need to make the most of your time by being outgoing and promoting yourself.

Always remember to be persistent, patient and unfailingly polite. If you say you’re going to do something, like follow up with someone, do it. Take good notes and thank people along the way who have helped you. Most likely, you’ll need to apply more than one of these strategies in concert to get in front of a power-player.

Related: Inventing Can Be Fun, and Profitable. Here's How to Get Started.