When pinning your pieces
 

Do you pin up and down or straight across? I have always done straight across but the women in the videos I watch pin up and down. Is there a difference?

Your usage of the terms "Up and down" vs. "straight across" confuse me.

Do you mean: When pinning units together for piecing do you pin perpendicular to your seam line or parallel to it.

If so...I pin perpendicular to my seam line. I can't imagine pinning parallel, unless you are hand piecing and even then that would be a bit cumbersome because you would have to remove the pin long before you get to that area for stitching. By pinning perpendicular to the seam line, especially when machine piecing I can stitch right up to my pin before removing it. In some cases I will stitch right over it if the placement is such that I am sure my needle won't hit the pin.

I used to pin parallel, but soon realised it wasn't working for me...saw someone on youtube do it perpendicular, and it does work much better in my opinion : )

I used to end up with bad seem intersections til I learned to pin on both sides of the seams with pins up and down.

Perpendicular to the seam for me. I feel like horizontal pins leave too much room for sliding.

I pin whichever way my machine likes in order to keep the two pieces together when sewing. In addition to the regular pinning - both sices of the seams, I also sometime put a long pin at the seam to keep the under seam going in the same direction as the feed dogs sometime twist it. The idea is to pin up/down; back/forth, sideways, or whatever to keep the seams matching.
Most of this kind of advise is based on what the person has found to work for them.

Boy am I confused. Could someone post a picture. I'm a visual learner. If someone can do this it sure would be a big help for me & I'm sure some others. I never gave much thought if there is a "proper" way to pin.

These links may be helpful.

http://www.justsewolivia.com/2013/02/best-practices-pin-perpendicular-to-seam.html

http://www.threadsmagazine.com/item/...t-way/page/all

I pin across the seam line. Makes it easier to remove pins before I run over them. I can also get closer to the pin before I have to remove it.