And if above tips don't help, glue baste! On the ironing board, line up the seams and pin. When satisfied that they match, put a small drop of glue in the seam allowance where they match and touch the iron to the seam allowance for a few seconds to dry the glue. I use Elmer's washable school glue. When your quilt is done and washed, the glue is gone. If the seams are matched when glued, they aren't moving while stitching.

I found it very helpful to pin each side of the seam after butting it together. I used to pin right up the seam and they would never come out perfect, now I rarely have to redo one.

Too much pressure on the presser foot can also push the fabric around, especially with multiple seams.

Here's a trick I've used for years to create perfect 1/4" seams and I sew strips together at warp speed using it!

IF your machine's feed dogs are NOT wider than the regular presser foot you use ----

1. Measure 1/4" to the right of needle strike (Use the stitched-paper method shown above).
2. Line up the glued edge of a small Post-It note (I use the 1/5" x 2" size), sticky side down, parallel to the edge of your presser foot at that 1/4" seam mark. (Like the tape does in the idea above.)
3. Use a fat rubber band from celery or broccoli stalks to wrap around your free-arm of the machine to hold the Post-IT in place. (I've found that the metal of any machine's throat plate will NOT allow the Post-IT to stick more than a few seconds.) This rubber band can usually be easily moved out of the way for refilling bobbins or making other than 1/4" seams.
4. A long strip of Scotch tape will also hold down the Post-It if you don't have a rubber band.
5. Align the edges of your strips/blocks with the edge of the Post-It and keep your eye on the front edge of it while piecing, instead of eyeballing the edge of the presser foot or the needle.

It's like this.......When we "drive" our machines with our eyes on the needle or the edge of the presser foot, we are driving like a 90 year old lady who is looking just off the hood (front) of her car to steer...she's got to make lots of tiny adjustments to stay reasonably straight. Looking ahead down the highway makes for much easier driving corrections.

Jan in VA

Thanks everyone for all your help. I will give it a go again. I just had to walk away for a time as I lost heart.

I butt and pin my seams first and then work out to the edges, works great for men.

I think we all struggled with this when we started. My problem was sloppy prep work. (I don't iron my clothes - now I'm supposed to iron fabric? You gotta be kidding!) Then I realized that prep work (accurate cutting, careful pressing, even seam allowance, and careful AND planned out pressing throughout the process) MAKES ALL THE DIFFERENCE IN THE WORLD. Pay me now (time and effort but a good end result) or pay me later (ripping out and redoing or a sloppy end result).

Don't give up on yourself. I think you are very smart for trying to identify WHERE your process goes wrong.

sunflower, where did you find the 1/4" foot with a lip? I have a plastic foot which has a 1/4" measure, but I think the lip would really be beneficial.

Janome makes (made) one originally, then other brands picked up on the idea.

My Post It note idea above works the same way but is MUCH cheaper!

Neither of them work all that well if your feed dogs are wider than your presser foot.

Jan in VA

Hi Joan - two things to try
- add starch to your process - I starch my fabrics before I cut - this makes the fabrics really behave
- I use a tailer's awl to hold the seams together right until the seam gets to the needle; I don't pin, just place the seams together as I'm going, then stick the point of the awl into the intersection and keep it there until it gets to the seam. You can still do this if you pin - when you take the pin out, stick the point of the awl in the intersection again right until it gets to the needle.

Hope this helps!
Linda