It took a while for Chloe to really get the come command. I just stayed calm and consistant. It takes a while but its worth the effort. I always had a treat bag with me (clips onto waistband) and every time she came I rewarded her with a treat. Then moved to giving treats randomly. Now she comes everytime
Like others have said your emotions have a big impact on successful training. A dog can really read your emotional state, they are smart little buggers