He always opens the door from the waiting room to his office and says "c'mon in." So I come in and sit down. Sometimes he stays over at his desk and finishes an email or something on his computer. He will sometimes say "talk to me" from this vantage point, and I will say some superficial stuff, greeting stuff, etc., but I don't like to delve into real stuff until he is sitting with me. When he comes to sit with me, he will usually just sit there and wait for me to start. He looks at me expectantly. If I don't say anything, he will sometimes say "therapist at your service."

Or sometimes he says, "whatcha thinking?"

Lately I haven't really wanted to start--I've wanted to take a little break and have less responsibility--so he's stepped into the void and done more of the "starting out" stuff.
There's always a little moment of tension when I take the plunge into what I want to talk about first. It's a little like that first dip of the roller coaster as it comes out of the gate. The tension is uncomfortable but also a bit pleasurable--the anticipation, etc.
I often feel shy at first so I will help us reconnect by using a starter topic that isn't as hard to get into as what I really want to talk about that session. The shyness is especially hard the longer we have been apart.