Who's thinking about taxes? The angst of April 15 is long past, and you've probably slipped into a pleasant state of disregard, where you'll dwell until some earnest end-of-the-year tax article jolts you into a frenzy.

There is a better way: Give yourself a midyear tax checkup right now. You'll cut your taxes more by doing a bit of lazy-days-of-summer planning than by scrambling around at the last minute.- Pay as you go . . . maybe. Many people worry that converting a traditional individual retirement account to a Roth IRA will force them to make quarterly estimated-tax payments this year. That's because most, if not all, the money that's moved will be treated as taxable income.

But the demand for estimated payments is triggered only if withholding from your paycheck falls at least $1,000 short of either 90 percent of what you'll owe in 1998 or 100 percent of what you owed in 1997. The 100 percent-of-last-year's-tax rule protects most IRA converters.

If you do need to boost your tax payments, get a copy of IRS Form 1040-ES, "Estimated Tax for Individuals" (1-800-829-3676, or www.irs.ustreas.gov). Once you know how much you will need to pay, you can decide whether to make estimated payments or ask your boss to boost your withholding.

- Down with withholding. Speaking of withholding, it's a good bet that too much, not too little, is being plucked from your paycheck each month.

The average refund was $1,342 this year. You can begin receiving installments on next year's refund by updating the W-4 form that's on file with your employer. For help, get a copy of Publication 919, "Is My Withholding Correct for 1998?" from the IRS.

- Give away a tax bill. If you need quick money to pay a child's fall tuition bill, give assets to your student and have him sell them and pay the bill himself.

Assuming your child is in the 15 percent bracket, he'll pay just 10 percent on long-term gains, compared with the 20 percent rate you probably face. But don't give away so much that your student provides more than half of his support for the year, thereby costing you the dependency exemption.

You can also give away a tax bill by making a charitable contribution with appreciated assets rather than cash.

- Now is the time to update the W-4 form that's on file with your employer, if you qualify for any of the tax credits or deductions that start this year.

First of all, if you have young children, drop this article and give each of them a $400 hug. That's what the new child tax credit is worth for each of your dependents under age 17. The credits begin to evaporate for couples whose adjusted gross income exceeds $110,000 and singles who make more than $75,000.

Older kids can cut your tax liability if you're paying tuition bills. The Lifetime Learning credit, which becomes available July 1, covers $1,000 of tuition expenses - 20 percent of the first $5,000 in payments - incurred by a taxpayer or her dependent for college, grad school or job-related classes. This is a one-per-family credit.

The Hope Scholarship credit, which has been available since Jan. 1, is worth up to $1,500 (100 percent of the first $1,000 in tuition, 50 percent of the second) per student, but it applies only to a student's first two years of college.

Because your children must be dependents for you to take these credits, make sure your almost-grown children still qualify. The biggest threat is probably the requirement that you provide more than half of their support.

Recent graduates who are not dependents may benefit from the student-loan interest deduction, which kicks in this year. If you're in the first 60 months of loan repayment, you can deduct up to $1,000 in interest - even if you don't itemize deductions. (The right to this write-off disappears as AGI rises from $40,000 to $55,000 on single returns and $60,000 to $75,000 on joint returns.)

Parents paying off loans used for their children's education can qualify for this break, too. Check with the lender now to see what - if anything - you need to do to certify that the interest you're paying qualifies.