All of the following is a guide for what not to do, which might leave best practices more obvious, but still utterly subjective.
TL;DR don't bother reading if you're looking for an obvious, objective answer, this question is, as stated above, utterly subjective. And best practices of software design ultimately conflict with any attempts to answer the question.
This is an interesting question because Microsoft has made a terrible effort at answering this question with their Ribbons in Office. And then successfully patented these fucking things.
That's insult to injury. Salt in the wound. etc.
Their stated goal was to make discovery of features and functionality easier and faster, but they did it in such a way that they put off the people that did know how to use more of the software, by removing the original processes of use, and adding steps to doing most things, too. Moronic in the extreme.
Microsoft has continued down this path with Windows 8's changes to the entire UI/UX and Windows 10 is not significantly better.
This is the biggest single example of what not to do, in the most prominent and dominant software on earth. So it's important to consider and learn from their lessons. Even though they haven't. And won't.
Similarly, "tip of the day" went out of style when Shareware did. Now it's just another window to click through that nobody wants to deal with, and is annoying.
Mastery is something that has to be encouraged. That means you must describe the benefits and find ways to entice the users to seek and find the powers of an app. This is as much marketing and advertising as it is UI and UX design.
Ice sculpture with chain saws is a really good example of this done right.
Interactive prototypes made with Apple's Keynote are similar.
Apple's Pages process of culling features is another wrongful step. Just because a lot of users don't use all the features doesn't mean they weren't the ones shepherding, teaching and otherwise guiding the majority of your users.
Odd how both Microsoft and Apple constantly move towards less concern for the ambassadors and thought leaders amongst their user bases, despite going in different directions in other aspects of their approaches.
Which leaves me with a very subjective answer: your UI and UX should empower simplistic and unmotivated users as much as possible without compromising the UI and UX for power users and those able to discover and learn on their own.
Perhaps I'm saying you have to accept that people come at tools with different objectives, talents and confidence levels, too.
And make videos about ice sculpting with your app.