I will attach a copy (both CorelDRAW and pdf files) of schematic symbols which I have saved in a file from which I copy and paste for other electrical circuits. I place the ones that I use in a key prior to the diagram. Labels may be added to indicate the the known values in a circuit -- the amount of resistance or number of volts in the power supply, whether a bulb is lit or not. Simplify without distorting the information. The number of long and short lines (and their order of placement) in important for the power supply. The filament in a light bulb can be simplified to a single loop. I hope you find this answers your questions.