You can easily traverse both ways in Neo4j. My usual default here is outgoing, that said... it depends on your model.
As an exercise, think about people and houses. Does a person have a house or a house have occupants Try thinking about relationship names here. Do they OWN the house, LIVE AT the house or what?
Person--{has}-->house
Person--{livesat}-->house
Person--{owns}-->house
House--{has}-->occupant
They're all slightly different relationships. Apply this thinking to your own model and go for what you think's best. I'm not a fan of "by" relationships, e.g house--{ownedby}-->person as they're simply traversing an "own" relationship backwards and are better expressed that way around.