So, in undulating terrain, the set-ups will be greatly increased in number as the team steps its way up or down the slope, limited by the practical height of the rod. The rod may be any extendable graduated pole or stick and there are many variations of that simple concept on the market. For greatest flexibility in varying terrain, a telescoping fiberglass rod of up to 25' is best. In Phoenix you probably don't need more than 13', although the uses these rods are put to often go far beyond mere leveling. In any event you should keep field notes of your work, recording readings as you go and maintain a close similarity to this illustration.
All readings associated with a given point are on the same line.
The FS value is always subtracted from the HI to produce the next known elevation. An IFS is a sideshot which is not subsequently used as a BS and therefore has an unverified value. The misclosure is 0.02' and is probably acceptable with no required adjustment to the sighted elevations. There are formulae for setting standards for loops but suffice it to say that you can expect some misclosure that may be distributed to every point as long as it is not excessive.