Matching seams gives a more polished and professional look to your quilt. Getting that accurate 1/4" seam allowance is a must but there are still steps you can take to get perfect matching seams.
Nesting the seams is the easiest way to get your seams to match.
Once you have stitched your rows together press the seams of the first row one way and the seams of the second row the opposite way.
Place your rows right sides together and where the seams meet 'nest' them together.
When you place the fabric between your fingers it should feel smooth, if there is a bump move the seams until they are flush, side by side, not one on top of the other.
Sew the rows together making sure the seam going under the needle is still flush. If the seams are not flush, gently pull on the top or bottom fabric to line them up. Try to pull the fabric slightly in from the edge so you don't pull your row stitches out. Once you have stitched across the first seam match up the next seam and continue stitching. Do this for all the seams in the row.
When you have finished stitching the rows press your new seam either open or to one side.
Your seams will match perfectly!
If there is one rouge seam that hasn't matched up to your satisfaction, don't take out the whole row. Instead, use a seam ripper to take out the stitches ~1/2" either side of the seam, nest the seam again, pinning if you wish to, and stitch again starting ~1" from the seam, pulling gently on the fabric to ease any excess in.
Happy stitching!