Easier manual invoicing

I would like to create an invoice without needing to have a “booking”… am I missing something? I’m genuinely confused. I don’t know why I can’t figure it out or it’s a design flaw.

It would be so much easier if I could enter invoices manually. It could be beneficial if when adding “additional services” in preexisting invoices there is a drop down with what ever services I have already pre added to my menu. Could also be helpful if we were also able to order the service item lines up or down to our preference.