There are several reasons for fudge stars not coming up tidy which are: 1. The star mold has not filled enough to fill the empty spaces in the mold. 2 You need to press the filled stars down with pressure to give them the exact shape of a star. Perhaps, you might have skipped this step. 3. The overfilling of the molds could also be one of the possibilities. Therefore, make sure to wipe off the extra fudge. 4. Furthermore, fudge stars are not given enough time to set.