Make sure your machine is threaded right, that can really screw things up for you (had this problem several times). Also, make sure you're actually turning the tension down (the lower the number, the higher the tension), some people get confused. Some fabrics just don't take to a sewing machine (stretchy ones are particularly bad), so it may just be the fabric and not you. If all else fails, then I'd turn to Google or something and go from there. The type of thread can have an affect too, for example, quilting thread and thin fabrics do not mix well.

Take a look at these photos and see if you can spot what might be the problem... the upper thread in the photos is blue, bobbin is red. The photos are in pairs. Loops on the bottom of the fabric = something wrong with the top tension; loops on top = insufficient bobbin tension.

http://www.picturetrail.com/sfx/album/vi...

You may have a dirty machine, a misthreaded machine, a machine with the thread catching someplace, or a thread that is not matched in size to your needle (the thread should be about 50% of the width of the eye of the needle -- side to side, not top to bottom).

can't tell from your description.

If you can tell us more about what your machine's symptoms are and which tension you've been adjusting, we might be able to come up with better solutions.

If you are unable to adjust the tension, it is time to take it to a sewing machine shop. They are sometimes out of time.

The tension on my Brother sewing machine is at it's lowest setting but there is still too much tension. I have tried every tension level but the stitching is the same. How can I fix this?