To be a good RPer, you must act as your character. PlaneShift is a reality, Yliakum is real life to those living in it, thus you must treat Yliakum like you do Earth. If you are a crystal, then you must sit there, not saying anything, not doing anything. Maybe weather when it rains? Have the tip of your body crack off and fall onto the ground?
If you were actually a human character, you would speak like you normally would, saying \"Hello\" or \"Greetings\" depending on how aged and knowledgable your character is. A three year old would speak in tongues, if being able to speak at all, not being able to be understood and so on. Someone sixty years of age, would speak like he has seen everything this world has to offer, he would be very knowledgable, able to give advice, able to fit into a public with ease.
Choose which best suits your character. Knowledgable? Delinquent? Silent? Motormouth? You get the idea.