Trying out the process, I had a look at doing it myself but I soon came a cropper over finding music that was usable but did not cost the earth. In the end, I turned to Fiverr.com and invested a small amount to have a trailer made for me. You can see it on my home page. I've had a series of comments including "very imaginative" and "straight out of "Pirates of the Caribbean" which it's not. European privateers worked in far less sunny surroundings! Looking at other possibilities now.
Then came the task of uploading the trailer to various sites including Facebook, Twitter, Vimeo, Amazon and this website. A pity Oneload.com is stopping in May - I got in just in time. Now to see if the video has any effect. Comments and constructive criticism would be very welcome!