April, June, September and January cover three, two, three and four months of income (sample note).
Tax notes
Short notes on returns, estimated payments, records and payroll, written for clients and anyone with a date coming up.
A short list of the papers worth keeping, and for how long (sample note).
Four quarterly returns and one busy week in January (sample note).
Sort by month, list what is missing, send it in one go (sample note).