I'm getting ready for my first Botox/filler treatment. How do I start to make it look natural?

I'm planning to slowly try small doses of Botox and filler because I have forehead and glabellar wrinkles and sunken cheeks. When I first visit the clinic, do they adjust the dosage based on my facial expressions? Rather than injecting a lot at once, I'm also wondering if it's safer and less noticeable to start with a small amount and wait about two weeks for a touch-up. Also, how many months do you usually think Botox lasts for the forehead and glabellar area? Does the lasting effect of filler vary depending on the area? What are the general reviews?

To reduce bruising and swelling before and after the procedure, is it recommended to abstain from alcohol, exercise, and saunas a few days in advance? I've heard that taking a break from omega-3s and painkillers (like ibuprofen) is also recommended. Is this actually effective? Lastly, to achieve a natural look, what areas should I be especially careful about (cheekbone/zygomatic arch, nasolabial folds, etc.)? Do you have any tips for maintaining a natural facial expression after the procedure? I've heard that it's helpful to record whether the photos are taken from the front, 45 degrees, or side. I'm also curious if this is how you typically check your results.