What is the ruling on my work in the field of decoration and advertising, which involves wood and metal ornamentation, with a request for a down payment, and is it permissible to give a gratuity to employees from the monetary amount?

There is no objection to taking an advance payment from the service requester. As for tips and sums of money requested by employees, these are not permissible except with the permission of their employer, because they receive wages for their work, and their request for something extra without permission is considered among the prohibited gifts to workers.