The U.S. Postal Service has hiked the price of stamps and is likely to do it again before the year is out.

First-class stamps are up to 18 cents now and prices, with a few exceptions, are higher all down the line for other USPS services.

As prices keep going up, it becomes increasingly important to cut your overall mailing costs wherever possible. John J. Daly, a consultant to businesses and government agencies on postal matters, offers these money-saving tips for mailers:

Check your postal scales. All too often, home scales or those used by small businesses are out of line. Plunk five quarters down on your scale. You should get a reading of one ounce. You may be adding extra postage because your scales are reading heavy.

Use Postal Service postcards. They're a bargain. The cards now cost 12 cents apiece, but that's still a lot less than the 18 cents you have to pay for a first-class stamp to go on an envelope. You can get a lot of information on a postcard. The Postal Service gives you the card free -- all you pay for is the stamp.

Watch out for oversized envelopes. If you just put a page or two in these envelopes, you'll have to pay a surcharge. It's better to fold the pages and put them into a regular size-10 business envelope. You can save at least 7 cents that way.

And if you do use large envelopes to send bulky papers, but the white kind with green, jagged edges. This signals the postal sorters to put the envelope in first-class mail. Big, brown envelopes tend to get tossed into lower-class mail piles and are delivered later. You might as well get what you're paying for.

Don't use special delvivery. It now costs a minimum of $2.10 to send something special delivery. And, the only thing "special" about it is the price. It's usually no faster than ordinary first class and sometimes is even slower.

Use express mail if speed is important. The minimum cost for a letter sent express is now $5.30 (down from $5.40). Depending on weight and distance, you can pay on up to $93 for this service. But it does get your mail there the next day.

Understand the difference between registered and certified mail. Too many amateur mailers believe they have to send important papers by registered mail. For the vast majority of situations, certified will do and it's much cheaper.

You pay 75 cents in addition to normal postage (down from 80 cents) to send a certified letter. If you want a receipt to show when and to whom it has been delivered, you have to pay 60 cents extra (up from 45 cents). To send a registered letter you now have to pay $3.25 (up from $3).

To save time (for businesses, time is money), mail your letters before 1 p.m. This beats the big postal rush-hour later in the day and can cut delivery time one to two days.

Don't use string with packages. Along the mail route, people tend to use the string as a handle, and it could loosen. And string might get caught in the sorting machinery. Use heavy-duty tape.

Q. I have one of those maintenance-free batteries which you can't check or refill. Recently it went dead. I'm sure the fluid ran dry. Isn't there any way to check the fluid levels on these batteries or refill them if they're low?

A. Maintenance-free batteries vary. Some have access for extra fluids if they run dry. But when these batteries run dry it's usually because something is wrong with your car's electrical system.

You should have batteries checked periodically to see how they're holding the charge and whether they're running down.

Q. I will be 65 in August. My wife will be 65 next month. We are both retired and are paying through the hose for health insurance. We want to cancel our insurance and wait until we get Medicare. Is this a good way to save on the $65-a-month insurance premiums?

A. No, it's not a good way to save. Keep your insurance until you get Medicare. Once you're on Medicare, your current insurance premiums should drop dramatically. Or you can cancel if you want. But stay covered until you're on Medicare.