Wow, what a lot of seemingly contradictory advice.
The main consideration is that the images need to be in a place where the browser can get to them - i.e., on the public side of your web site.
You cannot just create a folder within app and hope that the images will be visible to the outside world.
The simplest solution is to place them in your project/public folder and then access them with, e.g., <img src="/imagesfolder/image.jpg">
This is only true though if you have correctly set the document root to be the public folder.
The more complicated solution is to put them in the storage public folder and then create a symbolic link so that they appear to be in the project/public folder.
Ignore all the helper methods for now. Just type the path to the image in your browser address bar. Make sure you understand where the images are from the browsers perspective.