Well, you know, “spiritual”–pertaining to the cultivation of the human spirit or mind.
1. Cultivate self-knowledge. Introspect. Examine your motives, your feelings, your moods. Know thyself. I know I can get caught in a mode of reactivity with no self-awareness. This is usually how I end up engaging in unhelpful behaviors, such as cussing out fellow drivers, staying up too late watching stupid Netflix movies, and so on. The more I learn to monitor my mood, my feelings, my thoughts, the more I’m able to channel my behavior in desirable directions (chilling out behind the wheel, slowing down, going to bed, etc.).
2. Kill your ego. For perfectly understandable evolutionary reasons, the vast majority of us engage in constant reputation management. I actually don’t think it’s possible not to do this at least some of the time, but then I don’t think reputation management is intrinsically wrong or anything like that. That being said, it is possible to cultivate a correctable self–to admit wrongdoing or error, to apologize, to laugh at oneself, etc. For a variety of reasons, it’s a good idea not to defend our ‘reputations’ in a knee-jerk way. It’s ok to be wrong, it’s ok to make mistakes. You acknowledge them, and you grow. (When we do this, we by the same token cultivate a desirable reputation: the reputation of someone who does not cling to ego.)
3. Always* tell the truth. *you know, almost always. This is simply extending the ideals of self-knowledge and ego killing to the way in which we interact with people in our circle of trust. Telling lies is tiring, distracting, and potentially harmful to trust and to human relationships, which are, you know, the very stuff of a meaningful human life (for those of us who aren’t sociopaths!). Some people may be too dangerous to trust, or some societies may be hostile to certain truths (these are tragedies), so this isn’t an inflexible commandment. But, in general, being transparent brings great peace of mind, and makes possible very open and very healthy relationships (assuming all parties value truth in roughly the same manner). I try hard not to keep secrets, even ‘dirty’ secrets, from my partner. Our relationship is much better for it. And the peace our honesty produces may not pass all understanding (Bible joke, sorry), but it’s pretty nice.
 Further reading on evolution and reputation management: Robin Dunbar, Grooming, Gossip, and the Evolution of Language; Richard Alexander, The Biology of Moral Systems.