Since then I have learned that in order to run a business you need to have enough inventory all the time and for this I needed to make more items per day.
My "secret" for getting more done in the same amount of time is simple: I work on several items simultaneously. I never make one item from start to finish. Instead I do all my wire bending of all the jewelry I am working on, then all the soldering, then the filing etc. When I am done I usually finish a large bunch of items all together. I discovered that this is much more efficient. Making 4 items together takes only a little more time than 1 item alone. So I try to work in series of items at once instead of working one at a time.