Annotations that clarify instead of confuse
A few rules for using arrows, blur, and text to make screenshots easier to understand.

The worst annotated screenshots look like a weather map during a storm. Arrows, boxes, highlights, and text labels fight for attention until the viewer gives up. The fix is restraint.
Add only what you would say out loud if you were standing next to the viewer. If a mark does not answer the question 'what should I look at?' it is noise. Delete it.
Pick one color for all annotations and stay with it. A single high-contrast color keeps the focus on the content. Mixing red, yellow, and blue into one image turns a screenshot into a spreadsheet.
Use blur for anything sensitive. Emails, tokens, account numbers, names, and internal IDs should never make it into a shared image. One sloppy share costs more than the few seconds it takes to drag a blur box.
Good screenshot annotations do not explain everything. They point to the one thing that matters, then get out of the way. That is the goal.