You are correct in that it is the threading or the tension. What make
and model is your machine, which side do they bunch up on, and are you
absolutely sure you are threading it properly? Maybe we can find a
threading diagram for you -- there are some sites that post a lot of
them for free.

The other thing to try is to hold both threads when you start sewing so
that they don't pull back into the seam line and make a mess.

If you don't have a cheap piece-of-junk machine that won't hold its
tension (been there, done that, trashed the machine and got my son an
old machine from the 50s that works far better than the other one did
even when brand new) you may not be able to permanently solve the
problem without getting another machine, though.

chatty cathy wrote:
ok i am not a good sew person but i do like the idea of sewing..does
that make sense? haha
i have a sewing machine my aunt gave me with everything i need to sew
but when i begin to sew i stitch a few times and i think all is ok and
then BAM the stitches arent sewing on the fabric or they are bulking up
and are a big bundle of th reads and i have to go back and rip it
apart...i cant seem to get my sewing machine to just sew a straight
simple stictch..i seem to have this problem often..i think maybe its the
way im threading the needle or maybe the tension but i dont know what it
should be on..im an idiot to this sort of stuff..i have so much material
and threads and embellishmetns my aunt gave me and im wasting it by it
sitting there..