At the moment President-elect Ronald Reagan's choices for secretaries of state and labor were announced by press release Tuesday, Reagan was getting a haircut.

After the barber shop, Reagan stopped at Mariani's, the Beverly Hills tailor who has clothed him for about 40 years, to be fitted for the $1,350 morning suit he will wear at his inauguration.

Sunday, Reagan did not leave his Pacific Palisades house. Monday, he took a Marine Corps helicopter to his ranch to spend a day relaxing chopping wood and clearing brush. Today, his only scheduled activity was a visit to a meat locker where the cows raised on his ranch and butchered are kept until he comes to pick the meat up and take it home.

Reagan spokesmen here and in Washington say that he is actively involved in his transition from president-elect to president, but to outsiders it often looks as if he is on the sidelines.

When Reagan has played a major role since his election victory he has been masterful. Two days after his landslide win, Reagan held his only post-election news conference and generally succeeded in pleasing his supporters while reassuring those who had voted against him.

He followed up with his victory tour of Washington, a sort of week-long photo opportunity in which Reagan pulled into his orbit Supreme Court justices, senators, representatives, Washington's establishment, his Teamster supporters and journalists, winning applause and friends.

Yet, when Reagan is in California, as he was for more than two weeks following his first Washington visit and will be now until Jan. 5, he seems to be remote from the process of shaping his adminstration.

The clearest examples have come in connection with the selection of his White House aides and Cabinet officers.

Initially, Reagan planned to appear jointly with his Cabinet nominees, but that idea was scrapped in favor of a joiint public appearance by the first eight chosen, and he did not attend.

Not only did Reagan not travel from Blair House to the Mayflower Hotel for that presentation, he reportedly did not watch the entire event on television.

West Coast spokesman Joe Holmes said Reagan watched part of the 30-minute question-and-answer session the eight held with a crowd of reporters.

As he was when his two principal White House aides were chosen, Reagan sometimes has seemed unaware of the timing of Cabinet announcements.

Reagan returned from his ranch Nov. 14, and told waiting reporters at the Los Angeles airport that no decisions had been made on personnel. A few hours later, it was announced that Edwin Meese III would be White House counsel with Cabinet rank and James Baker III would be the White House chief of staff.

Meese, as director of the transition, has appeared to be at the center of all decisions while, accurately or not, Reagan has been perceived as less involved in the decision-making process. Meese also has been the most frequent public explainer of what the incoming administration is planning, appearing frequently on television interview shows and at sessions with reporters despite his heavy schedule of transition meetings.

During his second visit to Washington last week, Reagan seemed uncertain about the timing and arrangments for his first Cabinet announcements.

As he left a Capitol Hill luncheon last Wednesday, he was asked by reporters whether he would appear with is nominees the next day.

"I don't think the details have been worked out as to what method is going to be used. But I think we'll be telling you some news," Reagan replied of the event then about 24 hours off.

That evening, Reagan was asked the same question as he left Blair House for a dinner party.

"You know, I haven't heard beyond what I'm doing this evening yet, but I know that tomorrow you're going to have some announcements," he replied.

Reagan gives the impression, in the brief exchanges he has with reporters who crowd around him at every opportunity, that he is not always certain of his schedule.

On Monday, Reagan was asked whether he would hold any meetings with his advisers this week. "So far nothing is scheduled," he answered. "They're mostly in the east now," he added of his advisers.

Holmes insists that reporters are mistaken if they think that Reagan is spending most of California time resting in preparation for the job he takes on Jan. 20.

"There is a constant flow of staff information," Holmes said. One aide, Michael Deaver, who was named deputy White House chief of staff today, visits Reagan frequently, Holmes said.

In addition, Reagan dictates replies to many of the letters from personal friends or prominent people who have written him since the election. He also spends time on the telephone with Meese or other advisers, Holmes said.

"Most things are funneled through Meese," Holmes added.