It is hard to not do so, but do not take the rejection personally. Always remember, getting rejected by a exhibition jury does not mean your painting was terrible, that you are an appalling artist, that your work is worthless and you may as well throw your brushes away. It means they did not want to include that painting in that specific exhibition.
Do not read more into a rejection than this. You do not know the jurors and they do not know you. You can never know the reasons behind their ultimate choices, though you can guess, deduce, and speculate. (Local art club shows are different, of course. There people do know who is who and personalities or friendships can get involved in the decisions, but that is a different can of worms to a large juried show.)
Getting seven paintings rejected by five competitions is tough, no doubt about it. Sometimes people have success with the same paintings in different competitions, though there is no foolproof way of knowing what art society competition jurors are after because there are so many factors involved. But if you are painting in a traditional realistic style and jurors focused on contemporary collage, the competition will probably not be a good fit for you. There is no point in trying to get a painting of pears into an apples show. Conversely, if the same paintings keep getting rejected, then you have to concede that other people simply do not like them as much as you do.
Before you decide to enter, check the competition is suitable for your art. The medium, subject matter, and style. Do not make assumptions, but check the small print. For instance, "watercolor" is sometimes limited to transparent watercolor only and at other times include any water-based medium such as acrylics and gouache as well as watercolor paint.
Remember that larger, national competitions will have more entries, and thus it is harder to get in. Question your aim in entering competitions. If it is to enhance your profile or resume as an artist, enter the big, prestigious shows. If your aim is to sell, look for exhibitions aimed at buyers with lots of marketing to the public. If it is about winning prizes, consider regional and local shows with fewer entrants where the odds will be better even if the prizes are smaller.
Check who the jurors will be, what style and type of art they produce (if they are working artists) or favor (if they are critics) or teach. See who the leading members in the society are, and the style of art they produce. Also check what paintings were selected for the exhibition in previous years and what won awards. None of this will tell you exactly what might be accepted this year, but it is a starting point for getting a feel for the type of work that has been included and thus might be again.
Do not mimic a juror's style of painting in the hope it will get you accepted. No-one likes to have their style copied, and your work may be seen as unoriginal.
Do not forget to compare the size of your paintings to what was in last year's show, as the final selection may include choices based on what will fit a group exhibition. Over-sized paintings are less likely to be accepted simply because of the amount of wall space they take up.
It should go without saying, but be sure to follow all the entry requirements. Every single thing, even if you think it is daft. That is the way it is wanted, so do it that way. Do not get your paintings rejected for a technicality.
Ensure your writing is legible, that you have provided all the information requested, and signed the forms in triplicate if necessary. Double-check the requirements for framing (or not) and that you do (or do not) have a hanging mechanism (such as d-rings and wire) as stated. Again, do not get rejected for a reason that has nothing to do with your artistic skill.
Do not enter an okay or nice or safe painting, enter your best work that fits the competition criteria. Submissions are accepted or rejected within seconds; you wouldd probably be horrified how quickly the initial choice is made. You want the "wow" emotional impact to hit the jurors, not generate a "yuck" or "boring, seen-that-a-hundred-times" response. If you do not think the painting is exceptional, why would something else?
Jurors are looking for creativity and originality, which in most competitions is not synonymous with cutting-edge, earth-shattering, in-your-face difference. Something that is appealing, catches the eye and pulls you in for a closer look. Something with a strong composition and solid technical skill (no paint flaking off!). You can not know what this definitely will be in the juror's eyes, but if you can not decide for yourself which are the best from amongst your paintings, ask your friends (both arty and not) which they prefer.
If you have enough good paintings, enter the maximum number of pieces the competition allows as it gives the judges a chance to see more of your work, that you are not a one-hit wonder. But ensure they are all of an equal, consistent standard, representative of the quality of your body of work.
If you're asked to provide a biography or artist's statement, keep it straightforward and short. Do not try to "sound fancy" or put it into "art speak", and don't fib about going to art school. If you are a mostly self-taught artist, say so. It does not change what your painting looks like. Ensure it sounds sensible; if you don't know what it means, how will anyone else?
• See Also: Juried Art Shows from a Juror's Point of View