Apache License 2.0 for workflows and medium-large software projects and libraries that should be integratable, or where you may get contributions (as it automatically applies itself to contribution received and adds patent suit protection). For larger datasets that may have mixed licenses or attributions.
MIT for small useful snippets you may want to copy-paste other places including GPL 2 (Apache only works with GPL3 because of said patent protection). (BSD 2-Clause is a variant of this, but less explicit about what is allowed)
CC0 for examples, metadata and JSON-LD @context that should be possible to copy/merge WITHOUT any attributions or license.
CC-BY 4.0 for documentation, preprints, white-papers, reports, logos where you WANT attribution for. For non-complex standalone datasets.
GPL3+ if you are making a new software application which potentially could make money on its own. AGPL3 if that application is web-based.
LGPL3+ if you have to make a library to fit into a GPL app or you are making a app like above, but want to allow third-party plugins to be commercial.