I found out that a sharp new needle (I change it ~every 200 000 stitches) and tearable backing (I use 2 layers), are very important, I also use silicon spray lightly during stiching. I glue my sandwich with 3M sticker spray and my needles never come messy...I think most mportant point is that your work doesn´t stretch up and down like a drumskin...Good luck!
