The first step towards getting your dog to ignore distractions is to include them in training from the beginning. When you introduce controlled distractions, you can help your dog to "win", therefore building confidence and love for work.
This video demonstrates very simple distraction training. Here are important details:
Lyra likes her toy; holding it is probably worth a "5" on a scale of 1 to 10.
Lyra loves playing with me with her toy; that interaction is probably worth an "8".
Lrya takes her dumbbell as a trained behavior; I have no idea what she thinks about it, but I doubt it's more than a "2" on a scale of 1 to 10.
In this video, Lyra has a choice. She can follow my request to hand me her dumbbell. If she does so, I will play with her and the ball (an "8"). Or she can ignore my request and hold her ball (a "5").
From eight weeks of age on, Lyra has learned that it is in her best interest to follow my directions - I can make it worth her while. Now it's simply habit, so she knows what to do when she is confronted with distractions. I train with toys all over the training yard, which I may or may not pick up. I welcome any distraction that I believe is less important to her than what I have to offer.
When you're working through distractions, start by showing your dog the options. Eventually, you'll simply allow distractions to be present. In this video, there were no mistakes. I did not have to remind Lyra to choose her dumbbell, nor did I have to show her how much fun it is when she makes the choice to listen to me. It is habit to make good choices. If she had made a mistake I would have waited. Odds are pretty good that she would have put down the ball and picked up the dumbbell. If she did not make that choice, then I'd presume that I had not done the proper foundation work, which would have involved tiny distractions that require little or no real challenge.
Work is what we do together; it is always interesting and engaging for her. That is my job.