The phrase "an usual method for" is not correct in written English.
The correct form is "a usual method for" because "usual" begins with a consonant sound.
Example: "Using a usual method for data analysis can help streamline the process."
Alternatives: "a common method for" or "a typical method for".
The exploration of this question starts with an analysis of the usual method for estimating the heat of gasification of solids due to Tewarson & Pion.
Because of its peculiar nation-to-nation character the usual method for an individual to seek relief is to exhaust local remedies and then repair to the executive authorities of his own state to persuade them to champion his claim in diplomacy or before an international tribunal.
My usual method for perusing a cookbook is to open it up and see where it takes me.
Unusually for Gibraltar, there was a long delay between the shootings and the setting of a date for the inquest (the usual method for investigating sudden or controversial deaths in the United Kingdom and its territories); eight weeks after the shootings, the coroner, Felix Pizzarello, announced that the inquest would begin on 27 June.
Even replying to unwanted messages with "NO" or "STOP" — the usual method for unsubscribing from an unwanted text message list — may only verify to spammers that you have a working number that can then be resold.
The usual method for initial assessment of an acute asthma attack in the emergency room includes the use of peak flow measurement and clinical parameters.
He noted that meeting a spoof target in person is not his usual method for obtaining permission, but was necessary in this instance to meet the album deadline.
The usual method for testing the adequacy of a model is carried out by computing the F-ratio of the lack of fit to the pure error and comparing it with the standard value.
The usual method for this is to sketch a first line from the point of view in a 60 degree angle to the left and mark your vanishing point where this line intersects the horizon.
