I was asked to also mention a few things in light of interaction and conversing as well as post-interacting with other characters.
When you do interact with a character, it is hoped that one would read about the particular character you are going to introduce yours to. By going into the applications, read about the character you are going to be playing with. Reason being, you need to keep in mind about their abilities, age, weakness, strength, type and place in the scheme of things.
For instance, the things you should keep in mind and question are:
"How much older/younger is the character that mine will be against/with/fighting/sleeping with?"
"What would be the effects if my character __________ with the other?" obviously fill in the blank with the question you have in your mind.
"My character is (this type, God, Hellion, Neutral). How would they interact or react to one another?"
Keeping these questions in mind, you NEED to remember blood type/mixing/drinking/feeding. Does age, element, type or ability play a factor in healing/consumption/ritual/mingling? Would their element be a match or be like oil on water? How would their level of maturity or thought process be at a particular age? One instance is the newborns of couples. They will, of course, be very new to many things and be most certainly only just beginning to explore avenues. Please remember (due to a recent misunderstanding) that even though a character is new born, they aren't born with knowledge and can still act like a toddler or a child. They do not have the proper thought process to understand reactions/interactions/behavior. If it is brought up, please be considerate of the player and ask questions instead of insulting them. It's only the mature thing to do instead of it being blown out of proportion.
Keeping character interaction in check, there is more plotting that can be done, more friends/enemies/lovers/frienemies that can happen with the proper handling.
One thing to DEFINITELY remember. If you have a question about the character, please PM or IM the player and ask, don't assume. That way, no misunderstandings will happen, and people as well as players can get along.