There is always one more adjustment available. A sentence could be smoother, a color slightly different, an edge a little neater. The project continues because stopping feels like declaring that no improvement is possible.
Define the purpose again. What was this piece meant to do? If it communicates the idea, serves the intended use or completes the exercise safely and appropriately, it may already have reached a reasonable ending. Perfection is not the only standard available.
Distinguish a necessary correction from an optional refinement. A structural problem, factual error or safety concern deserves attention. A preference that changes each time you look may be better explored in another version.
Give yourself a final review with a specific scope. Check the relevant details, make the changes that clearly serve the purpose and then put the work aside for an appropriate period. Constantly returning to the same uncertain detail can make judgment less clear rather than more precise.
If the piece is for someone else, confirm the agreed requirements rather than adding endless extras they did not request. More work does not automatically make the result more useful or more generous.
Record ideas for a future attempt separately. You can learn from this project without requiring it to contain every lesson before it is allowed to end. A finished piece can remain imperfect and still provide the basis for better choices next time.
List the changes that are necessary for the piece to work and separate them from changes that would merely make it different. A missing fastening, an unclear sentence or an unfinished edge may belong in the first group. Another color experiment may belong in the second. This distinction is easier to make when you return to the original purpose of the project instead of comparing it with every possible version.
Choose a final review point, then store or display the completed work appropriately. Keep a note of ideas for a future piece so they do not all demand to be added here. Finishing does not mean declaring that improvement is impossible. It means allowing this particular object or text to exist as a coherent version, with enough of its questions settled that you can turn your attention elsewhere.
Then complete the practical closing steps: store or present it appropriately, clean the equipment and return unused materials to a usable condition. Ending is part of making. It gives the work a place in the world and returns some attention to the next thing, instead of leaving every project permanently open as a question you are never quite willing to answer.
A little more room to be yourself.