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.
Template messages vary in their placement. For example, a {{merge}} notice goes at the top of the article, but the {{stub}} message goes at the bottom. Read the documentation at the bottom of a template for instructions on how to make use of it.