If you are an inventor, you could license your patent to a company. In licensing deals you normally get a percentage of sales. The best way to license your invention is to seek out manufacturers. Technically, it is called licensing your patent rights.
You want to start out by developing a list of manufacturers. Look for those that are already making products in your target niche. One or two manufacturers is not enough. Identify at least, 25 potential manufacturers.
You can find manufacturers by looking at product packaging, online research, networking, and visiting trade shows. Libraries have excellent resources to locate manufacturers. Thomasnet, WikiMachine, ManufacturerUSA are possible resources too.
Reach out to manufacturers with a short message about your invention. Provide enough information to trigger interest, but don’t overwhelm people with data. LinkedIn can be an excellent resource to find the appropriate contact person.
Consult with an experienced licensing attorney before you enter negotiations. Ultimately, the licensing agreement will include details about upfront payments, exclusivity clauses, percentages, and infringement issues. You could really do yourself a major disservice by entering into an agreement without professional help.