Inventors are always looking at existing products to see how they can be improved and will contact company's with these improvements hoping for a licensing deal. This is where the tricky part comes in when you come up with these improvements. Is your idea an improvement to the existing product or would it be considered an accessory to the existing product? This can make a huge difference in how they look at your idea.
Here is a situation an Inventor friend of mine ran into when contacting a company. He told the company he had come up with a product that would make taking their weedeater head cap off easier. He stated he came up with the idea because the current model cap they make is horrendous to remove. (His word not mine). They passed on the idea. He showed me his prototype and it did exactly as he stated. So he was confused why they would turn it down.
I told him to take another look at his pitch to them and REALLY read what he wrote and if you were the company how would you have taken it? He read it several times out loud and said "I still don't get it." So I asked "What are you telling them about their product that might be insulting?" He sat there a minute and said " That their weedeater head cap is not designed right." Then I said "And you are telling them they need to sell consumers a special tool in order to take the cap off. Which makes it look like their product is a pain in the butt to use. Is that the message they want consumers to have about their product?" He laughed and said "Not a good PR move".
Inventors need to look at what they come up with as improvements and think about it from the companies side and would it send a positive or negative message to a consumer? Also consider accessories to existing products as a great alternative. Companies love having additional things they can sell you to a product you already use. If my friend had come up with a new weedeater head attachment that accomplished a different task but used the existing weedeater connection that is something that would get more attention from the company.