The one writing guideline that has altered my writing the most is the Show vs Tell guideline. I was probably far into the "tell" territory before, but sometimes I feel like this guideline is restricting my writing, as I sometimes opt to just give up when met with challenges like showing complex and nuanced emotions instead of just telling them. I just think, "the reader is smart enough to realize what the character is feeling given the context and prior characterization."
When I was talking with a crit partner, they once told me that when it comes to Show vs Tell, it is really showing emotions that is most important. Everything else can be told or shown, not really important. I took this advice to heart and stopped writing more tell-y things like "A face of wintry bleakness", or perhaps of a more common quality, "A face of fuming anger". Instead, I started trying to describe their facial expressions, because just writing "A face of fuming anger" is really the same as writing "His face looked angry/He was angry".
And sure, this advice works fine for simple emotions like anger, sadness, etc. But for more complex and nuanced emotions, it's difficult. An example:
In my book, a friend is telling another friend that someone in his tribe might be alive. This friend had thought their entire tribe was dead, and this had put them into years of apathetic hopelessness and indiscriminate rage. When he is informed by the possibility of a tribe member's survival, he is naturally flooded with hope. But this feels strange to him, and more importantly, dangerous. It's the typical being afraid of hope because of how it raises the stakes. Their avoidance of hope has become a defense mechanism. As such, I wrote
Tseena looked up with him with a face of reluctant hopefulness.
Not very creatively written in it of itself, but that is within my ability to spice up. What I'm really uncertain about is if it is fundamentally off on the wrong foot. It is blatant telling, but is that okay, even if I'm actually telling an emotional state? How does one even show something like "reluctant hopefulness", or another emotion that is more nuanced and complex than just happy, sad, angry, etc.?