XrmToolBox
The mandatory free tool to work with Dynamics. It has the most diverse types of plugins to work with views, fetchXML, dashboards, data migration and tons more.
Ribbon Workbench
The unique and very best solution for ribbon customization. Build personalized buttons using visibility rules and give them JS commands. This tool can either be imported to Dynamics as a managed solution or use directly on XrmToolBox.
ProcessJS
A well-documented set of JavaScript functions created by Paul Nieuwelaar to call Actions and Workflows. Especially useful for integration with Ribbon custom commands.
CRM REST Builder
A powerful tool that saves you a lot of time helping to create requests via WebAPI or JavaScript.
Dynamics 365 Workflow Tools
Dynamics 365 Workflow Tools is a Community solution that expands Microsoft Dynamics 365 (CRM) Workflow features with lots of new functionalities not requiring code. My favorite one is the possibility to trigger calculated/rollup fields.
Scheduling Recurring Workflow
[Discontinued] One of my favourites recent discoverings is this amazing solution that Alexander Development created for the old problem of date-triggered flows. This approach queries records using fetchXML and triggers a workflow against the result. Pretty smart.
Knowledge references
It Ain't Boring
Massive catalog of articles and advanced techniques to bring your knowledge to the next level.
Engineered Code (YouTube)
A fantastic series of videos with tips for specific scenarios for Power Pages. The best source of learning I've found so far for the subject.
Matthew Devaney
A huge reference for tricks and best practices for Canvas Apps and Power Automate. An absolute must-have in the favourites.
FlowJoe.io
Handy tips to become a pro in Power Automate
Server-side plugin template (C#)
For some reason, Microsoft removed the template code from the official website that I believe every student has once used as a reference, so I'm making available a copy for use.