Under the prudence concept, do not overestimate the amount of revenues recognized or underestimate the amount of expenses. Also, one should be conservative in recording the amount of assets, and not underestimate liabilities. The result should be conservatively-stated financial statements.
Another way of looking at prudence is to only record a revenue transaction or an asset when it is certain, and record an expense transaction or liability when it is probable. In addition, you would tend to delay recognition of a revenue transaction or an asset until you are certain of it, whereas you would tend to record expenses and liabilities at once, as long as they are probable. Also, regularly review assets to see if they have declined in value, and liabilities to see if they have increased. In short, the tendency under the prudence concept is to either not recognize profits or to at least delay their recognition until the underlying transactions are more certain.