Before the model arrives, whether studio or an outdoor setting, I show up early, set up a head and shoulders dummy and play with lighting. This helps me make sure my gear is working, lighting is near right, and acts as a warm up for me, which helps shakes off some nerves. When the model (and entourage) arrives we sit down and talk for a while about what each of us is trying to accomplish with the shoot. I show samples of my work to see what the model likes and talk about poses. I try and put the model at ease, especially moms with kids, or moms and dads with pets, letting them know we can break at any time they want, if something makes them uncomfortable, they need to bring it up immediately so we can work though it as an uncomfortable model may not shoot well. I ask if they have any concerns before we get going. This talk time puts us all at ease.
The level and detail of the discussions change depending what type of shoot it is. Easy ones tend to be professional head and shoulder shots. Most of the time, we a done within an hour. Pets are fairly routine if the mom and dad can get them to sit or stand and stay for a bit. I always ask if mom or dad want to take a few shots with their pet. Before pet shoots, I ask for a smartphone pic of their pet so I can find a good background. Families and kids are a bit tougher as mom (usually) or dad are looking for that "something" in the shot. Beauty shots including pregnancy shots and shots for model portfolios, especially with wardrobe and makeup get very involved can be challenging and sometimes can take a whole day to shoot, a lot of set and lighting changes, and a lot of mem cards.
Something I find invaluable is to shoot tethered to let the model see their images on a larger screen before we wrap up.