I used to have one lamp clamped to a bookcase that was used to light either the cutting table or the ironing board. I also had a floor lamp that stood between the sewing machine and serger and I shifted that lamp between machines as needed. I recently bought two separate lamps for the cutting area and ironing board. The arrangement worked so well I applied the same logic to the sewing area. I bought two more lamps, one for the serger and one for the sewing machine, and mounted them on the wall so they directly lit the feed dogs. Previously, when the floor lamp was positioned for the serger, the light source was on the right and a shadow was cast directly on the sewing area. This new arrangement eliminated that problem shadow.
I encourage every sewer to critically examine the lighting in their sewing space. Then run, don't walk and buy more light. Your eyes will thank you!