Rule One :- The Headline
The headline should summarize whole offer. It should grab eye, and make you want to read subheading.
The headline should intrigue and captivate reader. It's sole aim is to make reader continue on to read body text. You should take great time and trouble over headline.
Let's say we're selling a book on home security, yes, I know, boring and you might start with something like this:-
"CRIME FIGURES UP"
This is very bad, but typical of an amateur. People don't care about 'crime statistics'. That's boring, they only care about their own house or car being broken into. OK, how about this:-
IS YOUR HOME AT RISK?
A bit better, but not brilliant. It does personalize it and does play on peoples fear. It's still pretty weak though. What we need is a headline that will grab you by throat and force you to read on. How about this:-
HOW TO BURGLE YOUR OWN HOUSE AND STEAL YOUR OWN CAR
Now that's what I call a 'killer' headline. You've just got to read on, haven't you?
Always think very carefully about your headline.
Make it extremely intriguing, interesting or exciting. If you're selling a 'straight' product, then use a slightly different approach, headline should state what product is, with a few adjectives in front. Say for a Tea Trolley, your headline would be:-
New, Italian, Fold-away TEA TROLLEY
There should also be a picture of product. The picture and headline simply act to grab eye of anyone who is remotely interested in purchasing this type of product.
Rule Two:- The Subheading
The subheading should expand upon story hinted in main heading, and draw reader inexorably into reading body text.
Subheadings for straight products should outline main features and benefits of product. Again, boring, but this is what works,
A subheading for Tea Trolley would be:- "New from Italy, Lightweight, Fold-away Trolley is available in your choice of three colors."
As I say, boring, but this is what works, so don't try and get clever or 'artsy'.
Here's subheading for security book:- "I've nicked hundreds of cars and done over fifty burglaries. Would you like to know what I've got in mind for YOUR place?"
Brilliant, or what??!! You've just got to read into body text, haven't you?
Remember this is MAIN function of heading and subheading. Notice quotes, it seems as though guy was talking to YOU, reader of advert, but quotes imply that it is just something that this burglar said, some time ago, to whoever it was he was speaking to.