I have never balanced a checkbook or paid a credit-card bill via snail mail. All of my banking, bill paying and statement viewing is done online.

Many other twentysomethings are in the same boat, as we've come of age financially with a wide range of technological tools at our disposal, from mobile banking on smartphones to budgeting on computers using software or Web sites. While the benefits of technology are considerable, the digital world may make it hard for some to get a tangible, firm grasp on their finances.

"Technology can help us, but it's not always a substitute for underlying fundamentals," says Joseph Montanaro, a financial planner with financial-services firm USAA. "It's like handing calculators to third graders without teaching them the basic math skills."

So, here are a few tried-and-true, "old school" financial tools that can help you lay a solid financial foundation:

A pen, a pencil and some paper. These are the basic tools needed to see your financial situation and plan a budget.

Sketch out a personal balance sheet, says Steve Horan, head of private wealth at the CFA Institute. List short-term assets such as checking, savings and money-market accounts; long-term assets like stocks, bonds and a 401(k); tangible assets such as a house and car; and liabilities, including credit-card debt, student loans and a mortgage.

Subtract your liabilities from your assets to get your net worth. This "gives you a sense of your financial position or financial strength," says Mr. Horan.

For budgeting, list in detail all your monthly spending, using highlighters to differentiate among categories, says Drew Denning, vice president of retirement and investor services at Principal Financial Group. Use that picture of your actual spending to set targets and spending limits for the coming months.

"There's something very personal and tangible about going through that exercise on paper," says Mr. Montanaro.

"It gives you something you can tack to the refrigerator so you have your own blood and sweat and handwriting sitting there saying this is what I'm committed to."

Envelopes. These are another old-school budgeting staple: You can control expenditures by divvying up cash from your paycheck into envelopes marked for various spending categories, such as groceries or entertainment.

Envelope budgeting uses cash -- an old-school tool in and of itself, notes Mr. Montanaro -- and when cash is gone, it's gone. In contrast, "with [credit] cards, you can buy things without thinking," he says.

A checkbook register. These are the booklets in a checkbook where you are supposed to record checks written, as well as deposits. Even if you're not writing checks, you can record ATM withdrawals and debit-card spending -- adding or subtracting all those activities from your balance.

"When you write down your transactions, it really anchors you," says Nancy Anderson, a financial planner with education firm Financial Finesse. "You know what you're spending and you see the balance."

When your monthly bank statement arrives, compare your detailed transaction history to the statement to make sure there has been no fraudulent activity or mistakes made by the bank.