Generally, there are four or five elements to a flyer or other publicity material: title, inspiring thought about Christian Science from the lecture, event information, lecturer’s name and picture, and perhaps a background image.
The title typically should be the largest font on the page so it doesn't get confused or visually compete with any other information on the page.
In addition to the title, it might be helpful to include one or two sentences that describe a key idea or concept from the lecture. But it's best to keep this copy brief so that it can have an impact on even a passerby — about 20 words maximum — and in a smaller font than the title. (The lecturer should provide this.)
The event information should be as simple as possible: date, time, name of location (e.g. "Springfield Public Library"), address, and sponsoring church(es). This information can be in a smaller font than the title also, and even smaller than the inspiring thought.
Traditional advertising in today's society heavily focuses on the image and personality of the presenter. In contrast, the draw of a Christian Science lecture is the healing message of Christian Science rather than the speaker. So we've found it helpful to keep the headshot of the lecturer relatively small and lower on the page, and keep biographical information about the lecturer to a minimum, perhaps only saying "Christian Science practitioner [and teacher]" and "Member of the Christian Science Board of Lectureship."
The background of a flyer can be a single color, a modulation of colors, or an image. If using an image, it's best when it relates in some way to the main message of the lecture, but doesn't distract from the other elements described above.
Less really often does do more.
The main idea is to allow these elements to work together simply and harmoniously. If there's too much information / text packed onto the page, people often won't take the time to really look at it.
Keep the focus of the flyer on the lecture.
Frequently, flyers include extra information, like church service times or Reading Room hours. Consider putting these on a separate page to be used as a handout (for in-person) or a slide (for web). This way, the focus of the flyer remains clearly on the lecture.
Above all, though, the most effective method of advertising has consistently proven to be the love and break-through prayers from the whole membership. Numerous times, branches have shared how new inspirations from within the membership in support of the lecture were the deciding factor for a healing and progressive lecture event. The neighborhood feels that love, that authentic Christianity, which is unwilling to accept surface level appearances as the context in which we must operate. It really makes a difference.