Best Practice - go simple and use the Google Patent search site and search all variations of name and function for what you are planning. This will help you become more knowledgeable as to what is actually out there and save you money when going to actually get an patent. THEN go do your market research to see if there is even a market for your product. There are all kinds of things that have been invented and never saw the light of day because the company had missed the boat when trying to actually develop the product, there was no market and they couldn't get any investors... so they had a nice certificate for their wall for the $30,000-$50,000 they spent on their patent.
I hear from patent holding entrepreneurs all the time that want an investor. Cart before the horse.
Once you know your product can be built (MVP) and their is a market for it and investors investing in that space (you can test the waters with your solution without giving up the secret sauce), then go to a patent agent first. It will cost you 1/3 of what a regular patent attorney would to get your paperwork started. With funding you can go do all the derivatives and build your IP portfolio.