More than anything, Ronald Reagan's political career has been based on his reputation as an evocative and inspirational speaker. He will try to do what he does best in his inaugural message tomorrow, delivering a speech described by those who have seen it as "tone-setting," rather than one that attempts to outline the programs of the Reagan administration.

"It is a speech in which the president-elect tries to set a tone rather than to make headlines," says Peter D. Hannaford, a longtime Reagan consultant.

Because of the nature of the occasion, the speech will, of course, "make headlines." But the hope of the incoming president and his close aides is that the message will ratify the Reagan campaign themes of revitalizing the nation's economy and restoring America's role in the world.

Top Reagan adviser Edwin Meese says the speech "includes the hope that there is a way out of our economic problems with a solution involving all of the people of the country, not just the people of this government."

Meese said the speech is thermatic and attempts to give a sense of direction but does not contain a laundry list of the president's proposals. Reagan is expected to give details of his initial actions in a series of messages to Congress during the first few weeks of his administration.

As inaugural speeches go, this one has been in preparation for a long time. Kenneth L. Khachigian, a former Nixon speechwriter from California who became Reagan's principal campaign speechwriter, started collecting memos for the inaugural address in mid-December. He received about 10 memos from senior staff members.

Reagan then responded to these proposals, telling Khachigian which ideas he liked and which he didn't. Khachigian then reworked the material.

"I served as the mechanic who did away with the dross and left the gold," Khachigian said.

It is an article of faith among political speechwriters that it is the politician and not the speechwriter who writes the address. But Reagan is a practiced speaker, and it is literally true that he likes to write his own material for ceremonial occasions.

Reagan, in fact, can be fussy about the language of a speech. During the campaign, to the consternation of his staff, newspaper deadlines were sometimes missed while the candidate reworked a speech.

The president-elect wrote most of his inaugural address in longhand, partly in pencil and partly in ballpoint pen, on a line yellow pad. He did most of the writing on a flight returning to California from Washington Jan. 8. He did the last page -- "the magic page," Reagan called it -- at his Pacific Palisades, Calif., home Jan. 10.

Since then, Reagan and his aides have been smoothing over the text and making minor changes. Release of the American hostages could require a further last-minute insert.

In preparing his speech, Reagan read the inaugural messages of other presidents. He told an aide that he found them interesting but that they hadn't been much help to him in writing his own speech, which Reagan wants to be a message that will speak to Americans about their present conditions.

If there is any president who inspired Reagan, it probably would be Franklin Roosevelt, whose original and famous inaugural address -- "the only thing we have to fear is fear itself" -- Reagan heard on the radio when he was a student at Eureka College. At the time Reagan was an unabashed Roosevelt supporter, and he could quote sections of the speech by heart.

The Reagan inaugural address in its present form is just under 2,000 words and is expected to take slightly more than 15 minutes to deliver.

In the campaign Reagan spoke from what his aides call "half sheets," which are standard 8 1/2-by-11 typing sheets cut in half. The speech is printed in large type because Reagan, who wears contact lenses, is nearsighted.

In his hundreds of campaign and banquet speeches over the years Reagan usually spoke from 4-by-6 cards containing key words that would trigger entire memorized sections of a speech. At the Republican National Convention, where he gave an acceptance speech that many considered highly effective, Reagan used a Tele-PrompTer. But as the campaign went on, Reagan became increasingly comfortable with the half-sheets, and this is the method he plans to use on Tuesday.