Cockatiel scared of target training.?

I have two cockatiels and I want to train them, so I started to separate them (one is would be in a cage in another room while I work with the other) and then I put them back after training. The problem is that my cockatiel is scared of the pencil I use for target training. Sometimes the bird would touch it and other times it wont do anything to it, even if I bring it (even millet) right next to its beak ( I also use a clicker when it touches it). How can I make this training effective so that the bird consistently touches the stick?