If you come to Tibetan Buddhism after having read one of the easily accessible books by the Dalai Lama you may be in for a shock: there are a LOT of rituals involved in Tibetan Buddhism. For Westerners the first responses will be alienation and curiosity.
To help you deal, here are some common practices. The main thing to remember is that this is about respect, not servility. A real spiritual teacher will help you develop your own wisdom and this includes your ability to think for yourself. (more about guru yoga)
When we prostrate to the guru, we’re really prostrating to the teacher as a vessel for the dharma.
Prostrating before teachers is about respect for that teacher. This does not imply listening without critical thought. In fact, my teacher stresses thinking for yourself every opportunity he gets.
Standing up when the guru comes into a room, passes by or leaves the room
Again: a mark of respect.
The guru sits on a throne
The oral tradition around my teacher has it that he didn’t want a throne to teach from. It was explained to him that the students would be sitting on chairs and would feel uncomfortable towering over him sitting on the floor.
That’s one explanation, but the fact is that in Tibetan Buddhism it is usual for the teacher to sit on a throne or pedestal. This is not as alien to Western culture as it might seem: in some classrooms at my old high school there were still pedestals for the teacher’s desk. The advantage is that the teacher can see the students better and they can see him or her better as well.
Incense and so on
All of the above is about respect. Respect for authority is a suspect attitude in Western culture these days. When a guru literally had incense burned in front of him as he walked into the room to teach, I felt a bit overwhelmed. However, for those with a Catholic background it is probably not at all offensive. In a Buddhist context it’s important to realize that it’s not so much the person of the teacher that is being honored, it’s the dharma, the teachings. That guru sat on a normal chair and wore normal clothes when he simply wanted to welcome everybody without giving any teachings. On that evening there wasn’t incense either.