I'm new to machine sewing and everything seems daunting. Stitch length, stitching styles, presser feet, materials etc.

I was going to practice a bit each day to get my technique up to speed before tackling a real job. 

The first hill to climb was getting enough thread together to fill a couple of bobbins and have some left for the top stitching.

After I went through a few spools of quality polyester thread I decided to give the offshore ( Chinese) materials a try.

I purchased a trail kit of 24 different colors and started my practice sessions by hemming pants and sewing T shirts. 

That's when I started having ball up and dropped stitches.

I took my machine into my local repair shop and they fine tuned it for me and I started again

Same problem!
I checked everything. 

Bobbins, tension, presser feet. 

Nothing helped. Worse was the fact that my problems were sporadic and I couldn't pin down the cause (s).

On closer inspection I found the Chinese thread ( bottom spool) was a good deal coarser than the Guttermen brand I have been using. There were also little tufts of loose material all along the body of the thread.

This was my eureka moment and I grabbed my needle stash and slipped in an 18 gauge on the machine and bingo! The problem vanished!

I have yet to tune down to the minimum size bore on the needles but right now the thread slips through the needle without binding and lets me lay down a thread pattern easily.

I will still use better quality thread for my better projects but at least I can stitch without problems with the less expensive Chinese stuff for the rest of my sewing. At about 20 cents for 100 yards (delivered) it may be something for some of you to consider.