The trick to balance is to not make sacrificing important things become the norm.
When leaders care less about their people, their people will be careless.
Work with people who believe what you believe.
Very few people or companies can clearly articulate WHY they do WHAT they do. By WHY I mean your purpose, cause or belief - WHY does your company exist? WHY do you get out of bed every morning? And WHY should anyone care?
Selfish is easy. It's sharing that takes courage.
The hardest part is starting. Once you get that out of the way, you'll find the rest of the journey much easier.