Do not turn back when you are just at the goal.

The last stretch is where most things are abandoned, and rarely because they had become impossible. Fatigue is highest, the novelty is long gone, and the finish is close enough that stopping does not feel like failure. Effort already spent counts for nothing if the last small part never gets done.

Identify anything of yours currently sitting at ninety percent. Give it a fixed block of time and finish it, imperfectly if necessary, rather than improving it further. The relief of having something actually done is worth more than the last few points of quality.