Character illustrations are needed in many ways for designing learning experiences. There are limited number of character sets within most authoring tools (with limited poses) and it is time consuming to design new ones from scratch, specially if they are supposed to have specific poses/gestures, or you like them to be "different". Here is a (very) quick way of making your own cool character illustrations, in minutes "literally"!

Let me start by cons! You are right! (Maybe not just yet :) but you will be after reading these coming lines). This will not give you vector-based illustrations, and well sadly you won't be able to put it on a billboard for example. If this is what you are after this technique is not for you. But if just like me you are dealing with many online courses/training projects and all you need is just something quick, cool and flexible, well, go on reading :)

Start by taking high res photos in all required poses, and then simply use one of many available online/desktop/mobile tools to apply the art/cartoon effects and see which one gives you the theme and color that you are after. Remove the backgrounds and convert to PNG and you are set. I know this looks stupidly simple, but it works GREAT! Just have a look at these couple of examples in this article taken from some projects. My clients "loved" them. Much more than the old-fashioned ones that were created with illustrator. Maybe that will be the case for your clients as well :)

Here are some (very) important tips though:

There are hundreds of tools but not all of them are suitable. I have tried "many" of them myself. The best one I have found so far is Befunky for many reasons (the paid version of web app not the mobile app which is not as good, it has a free tool as well but best cool stuff comes with the paid version) but I won't go through details here.

Only go for the highest resolution possible. Anything less than 4k res, forget it all at once. However, for some effects (like hand drawing ones) even lower resolutions might work ok, still for much cooler effects like the ones that I use the quality is the key.

Just like many other cases clean background is helpful and makes it easier for removing the background, etc. Also, some colors look better under specific effects. You will find about them very soon by experimenting.

You can use the same technique for some other visual design works like objects, backgrounds, posters, cover photos, websites, etc. I have started making animations this way. Again, works really good but needs another article.