Template:Done explains how to add Done to a talk page, Teahouse, etc. But that's not all! Dozens of other icons/images are available on that page. It's Great!
References
^Worthen, Mark. "This is a helpful template tool." Journal of Groovy Tools 27, no. 5 (2020): 56.
These are online tools I use all the time. All are free; none of them contain affiliate links. Except for the Wikimedia URL Shortner, these are all external links, i.e., not part of Wikipedia or its sister sites.
Wikimedia URL Shortner - Links to the following domains may be shortened using this tool: *.wikipedia.org, *.wiktionary.org, *.wikibooks.org, *.wikinews.org, *.wikiquote.org, *.wikisource.org, *.wikiversity.org, *.wikivoyage.org, *.wikimedia.org, *.wikidata.org and *.mediawiki.org.
Case Converter - Case Converter is a simple free online tool that converts any text to either lower case, upper case, proper or sentence case.
Remove Line Breaks - You can remove line breaks from blocks of text but preserve paragraph breaks with this tool.
Character Counter - Useful when you want to experiment with different short descriptions and see how close you come to the ideal 40 characters.
Sᴍᴀʟʟᴄᴀᴘs text tool - Create official looking Small Caps text with this tool, for uses other than Wikipedia. Small Caps are uppercase characters with the 'x-height' of normal text. Among other uses, Small Caps are used for Bluebook legal citations, although on Wikipedia small caps are discouraged for understandable reasons. If you want to use small caps on Wikipedia, use the Smallcaps template, {{sc1}} or {{sc2}}. That template explains its limitations in the Technical notes section. There is also a helpful section, Reasons to use small caps.
Many people know that if someone reverts an article more than three times in 24 hours (3RR), they may be blocked to prevent edit warring. But did you know that:
Although reverts on different articles do not count towards the limit, different reverts on the same article do count. So if you revert Paragraph A twice and Paragraph B twice in 24 hours, you have made four reverts and may be blocked.
If you revert three times, wait for 24 hours and start reverting again, you may be blocked for 'gaming' the rule. The three-revert rule is an electric fence, not an entitlement.
Although you cannot be blocked for repeatedly reverting vandalism, many Wikipedians mistake edits for vandalism when they are not. For example, edits that do not respect the neutral point of view policy are not vandalism.
The easiest way to avoid being blocked for reverting is to revert as little as possible and discuss with your fellow editors instead. Some editors limit themselves to one or no reverts a day. Select categories on Wikipedia are limited to 1RR (one revert rule). Those articles will have an edit notice to apprise you of their special status. For 1RR you may only revert one edit in the entire category per 24-hours.