However, I'm now starting to think that I should change this. I might start writing the steps to test a feature at the start of development. It can be thought of as similar to test-driven development. If I start the ticket by writing the QA notes for testing it, I can work against the notes.

It might carry all the same benefits as test-driven development. I'll get a chance to fully understand the problem at hand before I start writing code to solve it. If I notice something funny in the requirements, I can save hours of work by identifying it beforehand. Also, when I'm done, I'm done - there won't be an extra step left to do at the end.

I'm not saying this is how I'll proceed from now on, but I'll give it a try soon. There can't be any harm in experimenting. It either makes things easier, or it makes no difference.