As a grant writer I have found the Foundation Database from the Foundation Center (https://fconline.foundationcenter.org/) to be extremely helpful in finding funding. This site provides a collection of information regarding grant funding, the funder's preferences, grant geographic limitations, funder 's areas of interest, 990 information (which provides insight into what grants have been awarded, in what amount, and to whom), etc. You can use the information garnered to do additional research on the funding organization, their founders, board, etc. If you want to access the database for free, many libraries offer access. Call them to inquire. Otherwise, there is a subscription fee for use.
Any grant written should have the funder's point of reference in mind. Your grant presentations should be written as if the funder is looking in the mirror. It should align with the funders' view of themselves. When the funder reads your proposal, they should be thinking "I can fund that; it looks just like me." I hope this helps. Be persistent, concise, and make sure you follow all instructive advice on submission and deadlines. Best of luck.