Studying the marketplace is one of the best ways to come up with new product ideas. If you ask the right questions and look closely, you will find opportunities to invent everywhere. When you study the marketplace for ideas, you're all but eliminating the need to ask yourself whether people are willing to pay for your product and if they need and want it.

When you pull an idea out of thin air, you have to find out if there's actually a need or desire for it. Remember: you don't have to reinvent the wheel to come up with a great idea. I've supported my family for decades by making small improvements to existing ideas.

Here are five places to look for your golden opportunity:

1.With your competition. What do leaders in your industry have planned for the future? Where is the industry headed? These are big questions, but they can be answered in part by checking out your competitions' patent applications. Many patent applications in the United States are published 18 months after they are filed. I don't spend a ton of time perusing the USPTO or doing Google patent searches, but I like to know what my competitors are up to. Checking out other innovations can be a great way to jog your creativity.

2. Inside product reviews. Check out reviews on Amazon.com and other websites. What are consumers saying about products in your industry? What are their complaints? What do they wish were different? You may be able to come up with a better solution to a particular, persistent problem you now know people would pay for.

3. At trade shows. Trade shows are great places to discover opportunities for invention. They always have a special section for new products. This is the first place I visit when I arrive. The excitement and energy at a trade show is palpable. It's impossible not to listen to the speakers, make new relationships, enjoy the special events and not get fired up. There's always at least one speaker who focuses on problems plaguing the industry. Can you be the one to find a solution?

4. In the aisles of your local retailer. Talk to store managers and employees during a quiet time and ask them what kinds of problems customers are having. What are they looking for when they come in? Are they satisfied? They know what is selling and what isn't. There is so much knowledge to be gained simply by asking. Form relationships and tap into that knowledge to jumpstart your brainstorming.

5. In your online search results. There are many articles published online by writers who report on the minute ins and outs of an industry. For example, because I am still inventing for the packaging industry, I keep abreast of what's going on simply by searching for "hot packaging trends" online.

Identifying opportunities ripe for innovation is just the first step. You still need to put your creativity to use and come up with solutions to the problems you identified, inspired by the new trends in your industry. All of these tips share a common thread: In order to keep coming up with great new ideas, you need to stay up-to-date and question the industry you're interested in. Don't get complacent. Get creative.