A guide to designing accessible, WCAG-compliant focus indicators
A11y - Focus Order
The A11y - Focus Order plugin lets you add accessibility annotations over your designs for the interactive elements of desktop, website, and mobile applications.
Accessible Focus Indicators: Something to :focus on | Deque
Designing a focus style | Zell Liew
Where to Put Focus When Deleting a Thing
When deleting something you should generally move focus to the prior equivalent control or its grouping container.