Blood work for 16 month old
At my doc's office there are two people in the lab and they had me hold my son on my lap while one person held down the arm and the other drew the blood. Both my boys have had this type of blood draw twice (we live in an old house so lead is always a concern), one of them was squirmy and disliked being held down and the other was easily distracted by the nurse but the process went quickly and smoothly for both.
My daughter has blood taken from the arm at 10 months, and the equipment in the phlebotomy lab was so interesting to her that she was fine. She had a second blood draw at her 2 year appointment, but just from the finger. That one we got through by me holding her close and singing Mary Had a Little Lamb.