Starts and stops can be handled in a number of ways. When starting, first you take a single stitch to pull the bobbin thread to the top of the quilt. That way you can hold the two thread tails as you start stitching, or wrap them around the shaft of a flower head pin and pin it tight to the quilt top so the tread tails don't get pulled with the first couple of stitches you make. As you start to stitch, you can make a couple of backwards stitches to lock the threads, just like you do with a domestic machine. Repeat this at the end of the stitching line. As you have observed, this often looks messy in the end. Another way to start (or end) the stitching is to start with a few tiny, tiny stitches, barely advancing the needle, and then go on your way with a regular size stitch. If you are at the end of your stitching path, you likewise end with several tiny, tiny stitches, barely advancing the needle. The thread tails can be cut off at the quilt surface when you do this, as those tiny stitches are very secure. If you have ever tried ripping out any stitches so tiny, you understand just how secure they are. Another way to start and stop a line of stitching is to just start off and end with a regular size stitch, leaving both thread tails to be square knotted and buried, just as is done with hand quilting. This method gives the best "finished" look, but is also the most time consuming. I have spent in excess of 20 hours just tying and burying knots on quilts once the quilting is completed. Not something you can afford to do for every quilt, probably. So I think the type of beginnings/endings you do on a quilt depends on the quilt itself. If you want to win an award, or if the quilt is destined to be a treasured heirloom, the square knots and buried tails is the way to go, imho. If you are making a utility quilt, which you expect to be used and loved until it is in shreads, I'd choose another method.