I use the smallest needle possible.
For piecing I usually go with a 70/10 unless the fabric is unusually thick.
For quilting I can sometimes use just an 11, but normally switch to a 90/14.
If i see skipped stitches I know I need to go up to a 16.
This is what my quilt store suggested for needles.
PIECING use 75/11
QUILTING use 100/16
NEW QUILT..... NEW NEEDLES
Keep the needles that are being used with the project until it is finished. This way you KNOW how long it has been used and on what.
Worn out needles cuse alot of problems.
snagging bobbin thread