WWTD or What Would Tantek Do? is a clarion call that serves as a good reminder of how to get back to Indieweb basics.
Common things that Tantek does that we can all learn from:
First think though exactly what problem you're actually trying to solve.
A reminder to search for examples of prior art before jumping in with both feet to solve an ill-defined or non-existent problem; also don't reinvent the wheel if you don't need to. See also What is XYZ?
Don't forget to add your example/implementation to the wiki, so that others can see and learn from what you've done. It's also not a bad general life aphorism either...
If you're going to do something, implement it on your own site first.
Similar to the aphorism that you'll get more flies with honey, it helps to think about your work and creative brainstorming in a positive framing instead of a negative one. It's easier to create/build with positivity than negativity, which tends to tear things down.
An exclamation, typically in surprise, at something that is the opposite of Indieweb and thus makes no sense
A less common response, usually to something from the exterior world that is fed into one of the Indieweb related IRC channels which claims to be indieweb, open standard, or microformats related, but often isn't as well defined as it should be.