One of the most common mistakes I hear from entrepreneurs regularly is, "I don't even have a product yet, how can I possibly start to do marketing?"

My answer? If you only start marketing once your product is ready, you'll have missed the train. Now is when you need to start building an audience, establishing the brand, and testing product-market fit. Don't wait until your product is ready.

Here are five things you can do to begin your marketing even before your product is ready. 

1. Find out if people even need your product.

While your product might not be ready for launch, now is a good time to measure how much demand there even is for your product, Whether it's through surveys or interviews with potential customers, it's probably a good idea to figure out if anyone even wants a product before you start building it.

2. Start building your social media accounts. 

Now is the time to set up the infrastructure for your social media activity. Your company Twitter isn't going to set itself up. Once your product is ready, you should already have an audience waiting. If you only start setting up your social media post launch, you have missed a golden opportunity to build an initial community around your product. 

Even if you don't plan on tweeting or posting, you can still use social media to listen to what people are saying about the market, about your competitors, and if you're lucky, about what people want to see in a product like yours. 

3. Begin to produce industry content.  

Now, I understand why this might sound scary to you, since the last thing you want to do is give away what you're building and give your competitors a head start. That doesn't mean you can't start producing content about the industry, without even talking about your product. 

If, for example, you're building an artificial intelligence product, why not start writing articles on your company blog about trends in artificial intelligence, new developments in the world of artificial intelligence, and other content about your industry without even mentioning the name of your product?   

4. Initiate some interviews with leaders in your space. 

Interviewing people in your industry might be the perfect type of content to generate early on, well before your product is ready for market. 

When you interview people in your industry, you achieve three very important things: You establish a relationship with the leader who you are interviewing, you gain targeted traffic when that person shares the interview with their audience, and you elevate your own brand by associating yourself with that industry leader.

5. Establish relevant relationships with journalists.

When launch day arrives, you're going to want to pitch the press, right? How do you plan on doing that without knowing who you're pitching to and how they like to be pitched? 

Well before launch is the time to do that research and set up the foundation for a successful launch. 

In addition to the research, you can also start engaging with that journalist on social media, so when you are ready to pitch them, they already know you and are more inclined to cover the launch. There are many things you can do to prepare for your launch and none of them have to compromise the ability to remain under the radar.

Having said that, if it applies, you might want to ask yourself why you want to stay under the radar. Is it because you want to be first to market? Well then, you might be ignoring the fact that being first is meaningless, and perhaps even detrimental.

Google wasn't first, Apple wasn't first, Facebook wasn't first. They just did it better. In order to do it better, you might want to start sharing your idea with some close contacts to get their feedback. That is much more useful than remaining under the radar.