Tags vs. Text
Click the switch at the top left
If your "tags only" results are weak use less words or use "all text" to rummage through titles and descriptions.
Creative Commons
Almost always the best images
Restrict your search to the Creative Commons with "only", and use the "commercial" setting for commercially usable assets.
Seek Original
High-resolution images
Blue bars indicate flickr™ is holding an original. Linger your cursor over the image to display dimensions. For nothing but originals switch Seek Original to "only."
Safe Search
Play safe
Do not disable the Safe Search unless you're of legal age, in a legal country, promise not to tell your mom, etc.
