Hmm, mine aren't exactly hacks, but good habits.
1. Make sure you delete (use Eraser, not just empty recycle bin) every downloaded statement. Or bundle the whole program inside a TrueCrypt VD. They usually contain ALL account information and are unencrypted (unlike the program itself). They are HUGE security risks.
2. Double-Entry Accounting. Quicken does a really bad job of this. Categorize EVERYTHING! With a credit card statement, it's easy, but if you withdraw $50 from an ATM, make note of your purchases ($5 coffee, $25 groceries, $5 Hustler, etc.). Don't let Quicken just oblivionize that money into some obscure category, "Cash", "Misc", or the worst, "Uncategorized."
Double-Entry Accounting just means for every withdrawal there is another deposit or expenditure. Thus a $50 cash withdrawal moves money from BANK -> CASH, and is CASH until re-deposited or spent on some categorized expenditure.
Warning: This can be a very tedious job if you have a 401k or brokerage account within Quicken. Quick fix is to just ignore those accounts when looking at most financial reports you can make Quicken generate.[/list]