One message that has stayed with me from my trainee bookbinder days is the importance of having the design details of a project resolved before you start cutting and pasting. It makes sense, of course, and the risk of doing otherwise is that things will at some stage go pear-shaped.
On the other hand, if you find during the construction of your fully resolved project that what you are producing doesn't please you, then it is highly likely it won't please others and there is probably not much point in continuing.
This is about where I am with Curtains right now. I finished the first of the edition and it didn't feel quite right. I had a bit of a rethink and made a prototype of a second version, which also had its shortcomings. All the bits and pieces that had been carefully prepared and assembled over the last couple of weeks are now in the waste paper basket. This is obviously frustrating but I'm now far enough into version three to feel confident that scrapping version one was the right decision.