some links and resources for plotting stories
Blake Snyder's Beat Sheet - Explained
Save the Cat Beat Sheet Explained [with FREE Template]
The Snowflake Method was created by Randy Ingermanson, a theoretical physicist and writer, and approaches plotting from a step by step process. I found this method helpful for coming up with a longer plot to fit characters from short stories, or pre-existing characters I didn't know what to do with. It encourages exploration and simplicity. Though the article says its for designing a novel, I have also used it for planning individual chapters successfully.
Step 1: Summarize your story in 1 sentence (under 15 words) and avoid using character names. "John" is replaced with "Repressed gardener."
Step 2: Expand this sentence into a paragraph describing backstory/set-up, disasters, and the ending. Ingermanson recommends using 5 sentences: 1 for set-up, 3 for disasters, and 1 for the ending.
Step 3: Flesh out each of your characters with a one page summary including:
Name, 1 sentence character story summary (similar to the 1 sentence story summary), motivation (abstract), goal (concrete), conflict (what's preventing them from reaching the goal), and epiphany (what will they learn, how will they change.)
Afterwards you can then write out a paragraph long character summary expanding on the 1 sentence character story summary.
For writing an individual chapter, I like to write the 1 sentence character story summary stating what the character hopes to achieve in the chapter, what happens as a result of their goal, and how that impacts them. For example: "John wants to propose to Simon in a fancy resturant (want) despite Simon's dislike of romantic gestures (conflict), and as a result Simon breaks up with him (result), leaving John crushed (impact)."
Step 4: Using the story paragraph from step 2, expand each sentence into it's own paragraph. Each one should end in disaster, except the ending paragraph.
Step 5: Write a 1 page description of each major character and half a page for the other important characters telling the story from their point of view.