The phrase "a useful impression" is correct and usable in written English.
It can be used when describing an impression that is beneficial or helpful in understanding a situation or concept.
Example: "The presentation left a useful impression on the audience, clarifying the project's objectives."
Alternatives: "a helpful impression" or "a beneficial impression".
He curls his lip in a useful impression of a you-don't-impress-me teenager.
Caution is needed because the most popular programmes are rarely the best and most interesting – no Molly Dineen or Vanessa Engel documentary, or Paul Abbott or Peter Kosminsky drama would ever hit the Top 20 – but this annual chart does offer a useful impression of what most viewers most want from their sets.
It is somewhat arbitrary and has not been scientifically validated, but nevertheless, we believe it provides a useful impression of the degree of patient satisfaction.
Certainly, the careful way in which the Bush allies have begun to register their discontent -- almost always under the cover of anonymity -- has served to give voice to criticisms while reinforcing the politically useful impression that the White House might not be as bad as the environmentalists made out.
The results of this paper provide a useful insight into the impression the UK physical activity and sedentary behaviour guidelines for the early years makes on mothers.
Though "Beneatha's Place" leaves an impression that a useful dialogue has digressed into a lecture, let's hope that others adopt this playwright's impulse to keep the talk flowing.
Descriptions of this give the impression of a useful paradox in the sense above, so this might indicate some progress in the field.
Knowing how to make an impression can be a useful skill in business.
A useful index for evaluating two psychological impressions of annoyance, speech audibility, and the listening score, when listening to audio signals composed of monosyllables and words, while subject to meaningless steady noise is discussed.
As celebrity endorsements to political parties go, Daniel Radcliffe's declaration of loyalty to the Liberal Democrats appeared, on first impressions at least, to be a useful one.
He exudes success, which creates the impression that his enterprises cannot fail – a useful trait in the tempestuous art world.
