This is perfectly fine; you're simply reminding yourself the note is sharp.
In fact, editors and printers of music scores will sometimes do this for you. When this happens, you usually see the accidental in parenthesis to indicate they're not trying to double-sharp or double-flat the note, but that they're just reminding you. This is called a "courtesy accidental". The most common situation is that the note with the courtesy accidental shows up in the next measure after a measure that had had the same note modified by an accidental. By standard music notation conventions, in the measure that has the accidental, the note only has to be decorated with the accidental the first time it's modified in the measure, and then it's played the same way for the rest of the measure unless explicitly cancelled with another accidental. BUT, in any case the accidental only lasts one measure, and reverts to the default based on the key signature in the next measure without any notation required. If the note with the accidental was early on in a measure containing that note many times, its very easy to make the mistake of not reverting to the normal pitch for the key.
This is usually based on the results of "playtesting"; as part of the publishing process they'll put an intermediate draft in front of musicians and have them sightread it. They'll look or listen for mistakes, and if a musician makes a mistake based on something like carrying an accidental too far, they'll look at ways to mark that clearly. As a rule, unless a piece is an etude or other exercise meant to increase your proficiency in music reading, sheet music reading should be as easy as possible given the inherent complexity of the music it represents.