What is the best tool or set of tools to perform trademark clearance searches of designs and design elements for products/apparel?

Yes. That is the whole purpose of the USPTO filing system. Whoever is first to file gets the mark. There is common law usage which they could argue but first to file is generally upheld.

yes. Many jurisdictions have rights in a mark that arise simply from use. That said, it is not the same as the rights flowing from registration and in some jurisdictions, it is not available. A quick call to a trademark lawyer should allow you to clear up if the rights you get through use are sufficient for your purposes. Note: Branding and brand strategy is the most overlooked aspect to starting a business and a little expense now can save you a whole lot of problems later on.

I can help with registering your brand with Amazon. Contact me if you would like to talk.

The answer is: as soon as possible. Trademarks can take 1-2 years before you go through the entire process. You can apply for a trademark yourself on the USTPO site. Might help to have a lawyer or paralegal help you if you are inexperienced. A simple filing costs a few hundred in fees depending on the nature of the filing. (not legal advice).

Hi: The US Patent and Trademark Office has some great resources, including solid search functionality which lives at: https://www.uspto.gov/trademarks-application-process/search-trademark-database Kerby