In my business, I give services - specifically speech therapy services. So what I need to do is collect a custom list of information about the customer, and then charge them for between 1-3 services.

Right now, I can't figure out how to customize the information I'm collecting about customers. Does anybody have any creative ideas for how to solve this?

I've spent all day scouring the internet for different solutions - and can't find anything that isn't going to cost a lot of money. Any input would be great. Seems very simple, just adding custom form fields, but I'm finding it's not that easy.