Think of an idea you can phrase in precisely one sentence.
Now, elaborate it to 100 words. Give it more depth, spice it up with a metaphor, or add an example to clarify your point.
Scale it up further: write 500 words around the same idea. Make sure the entire text provides value and feels natural. Consider more nuances or different perspectives.
Notice what this elaboration does to how you think about the original idea.
Go back to something you wrote in the past. Pick the first 500 words and reduce them to no more than 100 words. Capture the essence of the original text — don’t lose its spirit.
Now scale down the text even further. Reduce the text to a single sentence — its core idea. Strip it of everything but its kernel.
Think of an idea you can phrase in one sentence. Now, express it using a single visual and no text at all.
You can take a photograph or find one; draw a sketch or plot a diagram. Any still image will do, as long as you think it captures the idea’s essence.
Share the visual with friends and see if they understand it without articulating it in words.