The villa household booking four arms at once
Think about sequencing inside the house. Children and anyone nervous about needles should go first, not last — watching three other people get drawn is the worst possible warm-up. For elderly parents, mention age and any blood thinners (warfarin, apixaban, even daily aspirin) at booking; the phlebotomist will use a finer needle where appropriate and hold pressure longer. If a household member has fragile or hard-to-find veins, say so — an experienced vendor sends their steadiest hands rather than whoever is nearest.
Households employing live-in staff often add them to the visit, and it is worth doing: a domestic worker's mandatory medical covers infectious-disease screening, not general health, so a basic CBC and glucose check may be the first real look at their health in years. It is a small cost next to the visit you are already paying for, and vendors handle it as just another draw on the same booking.