You've probably already received a lot of advice on how to invest your money in 1991. But any financial plan these days is worthless if it doesn't take into account the unique economic problems that many people will be facing this year.

The suggestion of a top financial planner, asked how to invest a hypothetical $50,000 -- particularly if you are one of millions of Americans who could lose a job in the months ahead: Make sure you can pay the rent before you even think about investing.

The nation's unemployment rate has been rising in the last few months, and experts predict that the number of people out of work will increase steadily in the months ahead. And for every person who actually loses a job there will be dozens of others who will be concerned that they might be next.

The nation's first recession in nearly a decade could also create the double whammy of sharply rising taxes (needed to trim government budget deficits) and paltry salary increases. So even those who get to keep their jobs will have less money to spend.

So what should you do? "I would first build a {financial} base, so that if you lose your job you could live for three to six months" on your cash reserve, advised James R. Hocking, chief investment officer for Citibank's private banking group.

If you don't already have that three- to six-month cushion, Hocking said, the entire $50,000 should be put into a money market fund or somewhere you can get at it on a moment's notice. Other financial advisers urged similar caution, although some warn that a three- to six-month cushion may not be enough. Nowadays, it is typically taking more than six months for most people to find a new job.

For those who can afford to invest the $50,000, Hocking thinks he's come up with a plan could make the nest egg grow to $100,000 in the next few years.

"One of the key words to keep in mind is quality," said Hocking. The other important things right now, he said, are to diversify your investments and to concentrate on the longer term, since no one can be sure what is going to happen in the next few months.

(Keep in mind that many people, myself included, think stock prices will go lower -- some even say much lower -- in the next few months before there is any sustained rally in prices. Pushing equity prices down, we pessimists think, will be a combination of factors, including the lower profits that corporations will be reporting during the recession, the Middle East situation and the profound trouble in the U.S. banking system.

(Bond prices should rise because interest rates are likely to fall. But there are a number of things -- including the banking industry's problems -- that could make even this seemingly simple prediction go haywire.)

Hocking would place $20,000 of the $50,000 in seven- to 10-year Treasury instruments. With bonds appreciating as interest rates decline in the coming months, Hocking believes the total yield from this investment will be "a solid 9 to 10 percent."

Another $25,000 should be put into stocks. Hocking likes some blue-chip companies, but not necessarily those that make up the Dow Jones industrial average. And he's also partial to the stocks of companies in basic industries, as well as those of consumer and capital goods manufacturers.

Some of Hocking's specific stock picks are Disney, Home Depot, PepsiCo, Wal-Mart Stores, Halliburton, Schlumberger, Alcoa, Waste Management and Cooper Industries.

Save $2,500 of the money that you earmarked for equities for small capitalization stocks. Hocking thinks small stocks are very cheap right now, but he would invest in these only through professionally managed mutual funds.

Hocking would have half of the $25,000 invested in stocks by the first quarter of 1991, and he would ease the rest of the money into the market in the months after that.

"This thing could turn around very fast," said Hocking, although he admits that trying to time stock market moves is often a futile effort.

The remaining $5,000 should be put into short-maturation certificates of deposit.

John Crudele is a columnist for the New York Post.