I endlessly tweak my designs, and even then am hardly ever completely satisfied with them.
I agree entirely!
Something I learned from @dfrazer is to save copies progressively, so that you can go back to a previous version that you worked on (say the day before yesterday) and glean ideas from the progress you’ve made. It can be encouraging. WARNING: This can be annoying if you’re a real ‘neat bug,’ because you’ll end up having like 20 versions of your file:
You get the point 😉
Another thing that might be helpful is to completely restart the project from scratch (again, keep the design you’ve worked on, it’s very good).
What that does is to help you to think COMPLETELY outside any mental box that the current project might have gotten you into. Do this two or three times, to stretch your creativity.