29.82Practical counterpoint recipe

For a melody you already know:

1. Write melody.
2. Mark long notes/rests.
3. Design a bass line.
4. Add a simple counter-line only in spaces.
5. Make the counter-line move mostly stepwise.
6. Avoid matching melody rhythm constantly.
7. Check vertical harmony.
8. Resolve strong dissonances.
9. Keep melody louder.
10. Remove unnecessary notes.

That will already produce convincing polyphony.