Maid salary

The physical payment of a domestic worker's salary should be accompanied by a receipt detailing the date, amount, and names.source: https://inquiresalary.com/za/domestic-worker-salary-minimum-wage/

below link may helps you. https://www.mom.gov.sg/passes-and-permits/work-permit-for-foreign-domestic-worker/employers-guide/salary-guidelines

I used to print out the record in A4 paper and get her to sign after receive the pay. Now using bank transfer

deposit into her bank account. set up a bank account for her and bank it in.

I just bank transfer, that is kinda like a record

Bank transfer. Easy and systematic