What about having an efficient communication between users, you could use Dynamics 365 InApp Notification to interact with user without disturbing them and keep a nice overviews of your tasks.
Dataverse : Multi-Table lookups or Polymorphic lookups is a GREAT feature that all of us are waiting since years ! Let's take a look on how to configure it and how it works.
When working with CRM Package Deployer, it always does an "Upgrade" process while importing a new solution. Please check out this post to find out more about the different solution update processes:
Let's see this nice Tips to use PCF for Dynamics 365 On premise v9.1. Indeed, PCF is officially only supported for Online version of D365, but with this quick unsupported tip you could use it either on on premise version.
Themes in Model-Driven Apps is a nice option out of box to customize the visual render and experience of your application. Check this out !
Security Roles are so important on Dataverse, Microsoft has recently implemented a new feature to make it even more powerful, to allow you to use different role on different BU level. So great. Please read this article on : Dataverse Modernized security model for Business Unit
Dynamics 365 : Custom chart with HTML and JS : Charts in CRM are very important and allow data to be represented graphically. However, the standard D365 chart engine is often limited ... Here is an alternative to create custom charts with HTML and JS.
Here is a very interesting new feature to improve the user experience on Model Driven Apps. It is about being able to use panels on the right side and to embed all kinds of web content. Come and read this article: PowerApps Side Panes Tutorial
Maybe you encontered issue with D365 Word Template not supported within Sharepoint ? This article gives you the details on how to solve it by using a nice trick.
Sometime when you are building some optionset you would like to add some nice icons to illustrate your label. Discover how to do it by reading this quick trick : Dynamics 365 Use icon in option set label