The best you can do.
I’m one of those people who likes to read about how the people I admire in business think and what they do to get the best from their staff. One example is Steve Jobs, co-founder and boss of Apple. Although for some he doesn’t set the best example (there are some stories you read about how Steve operates and you wonder whether it’s a) true or b) worth working at Apple), I like how he gets results and how some people churn out their best work.
A story goes that one of the engineers working on Finder (the equivalent of Windows Explorer) showed it to Steve, and Steve asked if it was the best he could do. The engineer said no, but was proud of it nonetheless. Steve handed the software back to him and told him to return when it was the best that he could do. (Source: Business Insider)
I’m aware that a lot of us software engineers work under time constraints (as do a lot of people in other industries), but with proper planning and management imagine what could be achieved if the work we did was always the best we could do.