I took a 6 week quilt course about 10 years ago, my first experience with quilting but with over 40 years of sewing. I still follow everything I was taught, except I do not wash my fabric anymore (unless it bleeds on my test paper). I think sewing with a scant 1/4 seam, pressing all my seams and measuring my blocks are the most important things. I have learned much more from my magazines, the Q board and just being around quilters. I think it's really important to change your needles and blades quite often and to always keep your sewing machine spotless. I have 3 generations of carpenters in my family and I think the important thing I learned was 'measure twice, cut once'.