Using Poor Quality Yarn or the Wrong Materials
Almost as important as selecting the correct materials is checking your gauge before you start. This means that once you have picked your materials, you get your crochet hooks out and do a test swatch using the recommended hook size. If your gauge is too large or small, you may need to use a different hook size, switch materials, or adjust the tension in your stitches. Skipping this step can lead to projects that are much smaller or larger than they are supposed to be.
Not testing gauge before beginning
Incorrect tension is a common beginner problem. If the tension you hold on your yarn is too tight, then your stitches will consequently be very tight. This will cause the finished fabric to buckle and warp and will also make it more difficult to get your hook into the stitches. On the other hand, if your tension is too loose, there will be a lot of extra space in between the stitches. This may not cause problems for projects such as blankets, but if you are making stuffed toys, the stuffing will come out through the holes.
Counting Stitches Incorrectly - Shrinking or Growing CrochetIt is very important to pay attention to the number of stitches that are meant to be done. Be sure to pay attention to the pattern and whether or not you are meant to count beginning chains. If your beginning chain is to be counted as a stitch and you do not, then you will do one extra stitch each row or round. This will cause your project to grow in a triangle shape. Also, be sure to go all the way to end of each row or round and put your last stitch where it is meant to be. If you skip the last stitch, your project will shrink length wise. The easiest way to avoid these problems is to count your stitches and use removable stitch markers if necessary.
Poor finishing techniquesA well-done project can be made shabby by poor finishing techniques. Be sure to weave in the ends of your yarn sufficiently that they won't come loose. This is best done as you go, especially if you have to change colors. Be sure that all your knots are secured under stitches so that they will not be worked loose through handling and washing. Finally be sure to take the same care with details and trims that you have with the rest of the project. Well done details can significantly elevate the overall look and quality of your finished project.
Crochet is a fun hobby with a nearly limitless opportunity for growth and creativity. However, it is important to avoid a few common mistakes from beginning to end in order to create a project that is both beautiful and durable.