Hi Surendra
Each and every parent here has been through that process. What we did at that age was to be really excited ourselves the whole week prior transfusion , treat it like a family outing. We used to talk on what we would do once discharged from hospital. Include the child in the discussion as to where he would like to go etc..etc...We never talked about the pricking apart, I never told him not to cry while pricking...nothing. We would carry a few tit bits he liked to eat, a few of his favourite toys.
Never lie to the child that she will not be pricked. At that age my son had to get a minimum of three pricks before they could find a vein. Once outside the treatment room he would still be crying , complaining the doc is bad etc.. etc.. and we would just agree with him, allow him to get it out of his system and in minutes he would be back to his normal self.
He is 6 years now and he still cries at times when finding the vein becomes difficult, but he actually enjoys going to hospital.