During the international Joomla Event JandBeyond in Germany three weeks ago I had the pleasure to present a talk on how to choose a Joomla Extension. I am happy to share the slides here with you now.
In short, my overall conclusion is: 'Less is More'. We see broken sites every day and have to tell clients every day that the fact you could install an extension doesn't mean you should!
Dummy Image Plugin has a variety of options available to make an image bigger, smaller, whatever color you wish, and even with or without a border. See examples.
Dummy Text Plugin let a single line of code render a full "Lorum Ipsum" dummy text. You can also do ordered and unordered lists or just single words. See examples
Remember, these plugins are free, and a terrific addition to your toolbox.