diff --git a/.dockerignore b/.dockerignore
index 8e02efbf0..cfdd63555 100644
--- a/.dockerignore
+++ b/.dockerignore
@@ -14,3 +14,37 @@
 
 # Ignore this in case the user previously did a "pip install -e ."
 qsimcirq.egg-info
+
+# Additional generic things to ignore.
+**/*.bak
+**/*.DS_Store
+**/*.log
+**/*.py,cover
+**/*.pyc
+**/*.swp
+**/*.tmp
+**/*.whl
+**/.*_cache/
+**/.git/
+**/.ipynb_checkpoints/
+**/__pycache__/
+*.cover
+*.coverage
+*.coverage.*
+*.egg
+*.egg-info/
+*~
+.coverage
+.dockerignore
+.env*
+.github/
+.idea/
+.venv/
+.vscode/
+bazel-*
+build/
+coverage.xml
+dist/
+env/
+jupyter_kernel.lock
+venv/
diff --git a/.geminiignore b/.geminiignore
index 947c71cec..bbc9603ef 100644
--- a/.geminiignore
+++ b/.geminiignore
@@ -19,3 +19,7 @@
 
 # Not in .gitignore because it's a git submodule. Tell Gemini to ignore it.
 /tests/googletest/
+
+# The next one (for Emacs versioned backups) _should_ be covered by *~ in our
+# .gitignore, but Gemini currently doesn't seem to interpret *~ that way.
+*.~*~