Fixington estimates stay on the job. Write the quote, send it, and change the lines when work is added or dropped, without losing what you originally sent.
Example
The quote is not a separate document you have to file. It belongs to that customer and that job, including jobs that do not have a date yet. That is how most trades work: price it, then book it.
Quote description, quote date and title are stored on the job. The title can follow your usual wording, or you can change it for this quote only.
Jobs move. A boiler service turns into a valve. A rewire picks up an extra room. Update the lines while you are there and send the quote again. You are not rebuilding the estimate from scratch, and you are not waiting until the evening.
The quote stays separate from the later invoice. You can still see that a quote went out, and what it said, after you have invoiced the finished work.
Send the estimate with the apps on the phone: email, iMessage, or another app you already use. There is no portal for the customer to learn.
When they accept and you agree a day, the job is already in the diary. The paperwork you did to win the work is the paperwork you invoice from.