Creative Accounting: How to check for inflated profitability

It is a well known fact that in order to get better valuations on the street, companies tend to inflate their profits. How do they do it ? In simple words, either by showing higher than actual sales, essentially inflating the topline. Second, don't show expenses by using creative accounting methods and not booking certain expenses and show higher than actual profit. The end result, higher earnings which create a rosy picture of the company and take investors for a ride.