What's not worth doing is not worth doing well.

Related:

• A thing not worth doing isn't worth
  doing well...
• If a thing is not worth doing,
  it is not worth doing well...
• Not everything worth doing is worth
  doing well...
• If something's not worth doing,
  it's not worth doing well...
• If it's worth doing,
  it's worth doing for money...
• If it's worth doing it,
  it's worth overdoing...
• Gordon's first law: If a research project is not worth doing,
  it is not worth doing well...
• Anything not worth doing is worth not doing well. Think about it.
  Elias...