Improve the shoebox.   Purchase a small portable file box or accordion style box.  File your invoices monthly and ask your accountant to provide you with unadjusted statements.
Ensure your records are complete and all invoices are filed in the box – a lot of calls are made for the 11th and 12th cell phone bills.  Have your teenager summarize all of your bills or enter them into QuickBooks.

Make your instalment payments on time to avoid interest and penalties.

Open a business banking account if you don’t already have one.  Keep personal and business expenses separate. Your bank reconciliation will catch missing expenses and ensure your records are complete and accurate.