Review and stage changes in pieces with git add -p

git add . stages everything, including debug prints, temporary files and unrelated edits. Staging in pieces keeps commits focused and doubles as a quick self review: you read every line before it is committed.

• git add -p walks through your changes hunk by hunk so you choose what belongs in this commit.
• git diff --staged shows exactly what will go in. Run it before every commit.
• git restore --staged <file> unstages a file you staged by mistake, without losing your edits.

git add -p                    # pick hunks interactively
git diff --staged             # check what will be committed
git restore --staged app.log  # unstage a file, keep the changes
git commit