How will I introduce juices to my baby? Using a dropper, feeding bottle, or spoon?

I agree with all the mummies who have commented. Introduce juices to your child preferably only after they turn 1-2, that too fresh ones. Now the fact that juices have the fibres removed while strained, will not help the child much nutritionally (if that's what you want). Feeding a whole fruit is always more advisable in terms of nutritional point of view.