Okay, a lot of people are going out on YouTube and making videos of collections of motivational posters. I've been guilty of it myself - it gives me something I can post on YouTube regularly so my subscribers know I'm still doing something. Now I'll share why mine are readable and other people's are not always readable.
1. Don't use the web pages that let you design your own motivational poster. They make the image size too large and then you won't be able to read the type afterwards. I do mine in PowerPoint and save them as JPEG files - there is a feature in PowerPoint where you can save your slideshow as several JPEG files. To do this, just click File, Save, select JPEG as the format for saving. Then you will be asked whether you want to save every slide or only the current one. Save every slide. It will save each slide as a picture file.
2. Allow enough time for people to read each poster. I set mine around 10-15 seconds each. My biggest beef with (most other) motivational poster videos on YouTube is that people don't think to allow plenty of time. If you use Adobe Premiere or Final Cut, there is a time stretch feature on both, but even programs included with Windows and Mac OS have similar features which allow you to display a still image over an amount of time. Not everybody can read at the speed of light. This also gives faster readers a chance to digest the picture and the words right, so they get what you're trying to say.
3. Oh, yeah, and make sure your concepts make sense.
Anyway, peace, love, and happy filmmaking until next time...