Sitting for Sternum

Hey guys- I have an appointment to get my sternum tattooed. I’m just feeling very nervous and am looking for advice on how I can sit well/be a good canvas despite my anxiety. I’ve talked with my artist about numbing cream to put my mind at ease, and he recommended one to me, and he’s been so helpful so far. I just don’t want to be an annoying canvas because of my nervousness. Does anyone have any advice on how I can sit well other than keeping my earbuds in?