Students have a legal right to be compensated for work authorized by any member of the faculty or administration. Those monies will be from other areas of the departmental budget than student labor. Realize that students have to study and complete academic responsibilities. Study takes priority over work. Talk out situations and keep small problems small.
Accurate communication solves most problems.
Verify and sign time cards for your students. If a card is turned in without the supervisor's signature, it will be returned for the supervisor to sign. No one likes to be paid half a month late. If possible, set up a time when you can be available to perform this function. Provide job description and meaningful tasks and functions for the student to perform while on scheduled hours.