The biggest issue I see with needles is size. People who stitch from kits often assume that the kit contains the needle they need to stitch the project. While this may be true in some cases, especially with kits created by the actual designer, often the needle included is either too big or too small for the fabric/thread combination provided.
With the notable exceptions of stitching through leather, paper, or vinyl, where holes are punched in the ground, you have some leeway in needle size. On woven and knit fabrics, it is better to err on the side of too large than too small. Let me repeat that, it’s an important point:
In general, it is better your needle be larger than necessary, rather than smaller.
I know, you don’t want to leave gaping holes in your fabric. If you choose your needle based on yourthread you won’t. Let me ‘splain. 
The eye of your needle should be slightly larger than twice all of the threads you put through it.
So, if you are stitching with two threads, it should be slightly larger than four. This is so that the needle will push the fabric out of the way enough that the threads glide through the hole with minimal rubbing. Friction on your thread makes it fuzzy, which looks sloppy AND makes the thread weak and prone to breaking. Also, using a needle that is much too small can break the eye when you force all that thread through the tiny hole, either when threading the needle, or more likely, when trying to pull it through the fabric.
Fabric is flexible. Use a larger needle (within reason) and the threads of the fabric will snap back into place around your stitching. If they don’t, especially with counted work, you can gently stroke them back into place. Too small a needle and the threads and the needle’s eye are under too much stress and may break.
So if you have a kit where most is stitched with 2 strands, and a smallish needle, and then it calls for 6 strands and the same needle, do yourself a favor – walk over to your needle box or book and pull out one that’s a size or even TWO larger for that part of the stitching. You’ll be glad you did!
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I didn’t realize there was so much to think about with regard to needles until I started thinking!
Part 3 coming later!
