I did not make many quilt before I realized how odd my first quilt looked. All it takes is practice, just like with anything else in life. This is such a broad field with so many techniques that mastering them all would take a lifetime. Like you, I had about 20 years of sewing experience before I started quilting. To this day I did not manage to have accurate 1/4" seam, BUT that being said all my seams are consistent, and for me that is the bottom line. I think that starting with simple quilts of your own design may be a way to go or following a simple pattern. You will be surprised how fast you learn. Good luck and we are here to help!