Given the Covid-19 situation, some customers may not be comfortable coming down to your place to get their measurements taken.
Instead, they may opt for a courier service. In this case, you should spend extra time communicating with them about the alterations they want to make.
You can choose QXpress or Ninjavan for your courier service. The additional cost will be borne by the customer, so do inform them if they choose to opt for courier service.