Water used to make up a can of Coke is direct water but water used to smelt the aluminum in the can and dispose of it and advertise the product is indirect water. The mix of water necessary to generate electrical power will be discussed in class. Let's NOT go there for this exercise. You may include hydropower if you know that is the primary non-consumptive water use for aluminum refineries, but let's not try to figure out the percentage of hydropower used to manufacture a silicon chip. You may choose anything, anywhere, to evaluate.
Food crops are easy because the data are publicly available.
An MP3 player is difficult because you do not know how much of what from what economic sectors goes into it. Automobiles are easier because you can develop generalizations based on weight and percentage of various raw materials and their manufacturing processes. If you choose a person or a profession, you should try to go beyond the simple direct water costs of that person as an individual. A river rafter does not consume the water she floats upon, but does in the gear that she takes with her. An Olympic swimmer does not consume the water in the pool but consumes a large volume of water flying to Australia to compete.