Prototype, then polish. Get it working before you optimize it

Given enough eyeballs, all bugs are shallow (e.g., given a large enough beta-tester and co-developer base, almost every problem will be characterized quickly and the fix obvious to someone).

When you lose interest in a program, your last duty to it is to hand it off to a competent successor.

The only way to write complex software that won't fall on its face is to hold its global complexity down - to build it out of simple pieces connected by well-defined interfaces, so that most problems are local and you can have some hope of fixing or optimizing a part without breaking the whole

Software is largely a service industry operating under the persistent but unfounded delusion that it is a manufacturing industry

Grovelling is not a substitute for doing your homework.

The next best thing to having good ideas is recognizing good ideas from your users. Sometimes the latter is better.