Save receipts and supporting documents for deductions.
The best system is the one you can maintain consistently. Many people scan or photograph receipts as soon as they get them, then save them in folders by month or tax year. You can also keep paper receipts in labeled envelopes or folders if you prefer physical storage.
A small routine goes a long way. Snap a photo of the receipt, name the file clearly, and add a note if the purchase needs explanation. That takes less time than trying to reconstruct the expense months later.
