The phrase "attempt often" is correct and usable in written English.
It can be used to suggest that someone should make frequent efforts to achieve something.
Example: "In order to improve your skills, you should attempt often to practice and learn new techniques."
Alternatives: "try frequently" or "make regular attempts".
And in the past year 5% of Salvadoreans suffered an extortion attempt, often orchestrated by mobile phone from prisons.
High-school graduates who do not pass the examinations on their first attempt often study intensively for a year and retake the tests.
Schools that do not appoint on their first or second attempt often feel their only option is to bring in a recruitment firm.
Destierro (1930; "Exile"), written shortly after he became secretary to the Mexican legation in Madrid, reflected the poet's attempt, often expressed in complex surrealist imagery, to rebel against a mechanized, hostile, and unfamiliar environment.
More commonly the theist will continue to include benevolence in the concept of God and attempt to deal with the problem of evil with the help of various auxiliary or even ad hoc hypotheses or considerations, much as a scientist may attempt, often successfully, to shore up against empirical refutation a previously well tested theory.
From a public policy point of view, it appears more appropriate to try to rationalize the practice than to attempt (often in vain) to prohibit it.
Well-intentioned rescue attempts often prevent such "orphans" from surviving.
By the ninth century, Islamic tower jumpers were attempting, often disastrously, to fly.
This brilliant, original playwright attempted, often futilely, to overcome Spanish theatre's bourgeois complacency and artistic mediocrity.
About the only thing they did well was shoot people, which Clyde and his partners attempted often, murdering at least 10 men.
Ranging over four generations, she identifies and isolates the points at which relationships start to fracture, and shows the tentative attempts, often years later, at repair.
