Practice, practice, practice. Additionally make sure your plastic is hot, this will allow for a thinner stream of plastic. Pour right down the center of the hole and pour slowly. I overfill completely to the top of the mold and let them sit for a minute then remove, trim the tops and repeat. It will be a little aggravating for the first few pours but as you pour more it gets alot easier . I hope this helps..
BassnG3