Find the best on camera acting teachers in your area and take classes so that you are comfortable with the technicalities of auditioning for the camera. Even if you have experience on set and acting for film, it’s important to know the specific needs and pressures that come into play when auditioning for the role.
Get familiar with the material being shot today. Don’t keep practicing recycled scripts from 5 years ago and make sure whatever teacher you go to is using sides from current or very recent projects. Things change and you need to get familiar with the details in the writing that make that script work. Practice makes perfect, but knowing what the writers intend, the tone and shooting style of this particular type of show, and how your character helps evolve that story will ensure that you can come into that room and do your job. It sounds very clinical and objective, but when you have a sense of those basic elements you will have more freedom to play because you won’t be wondering “what are they looking for?”