Maintain some distance to your partner before you actually break up. Just cut off contact for a week before. Do not give too much information, just say you’re busy. Do not delay breaking up it only makes the situation worst.
Do not create a big issue.
Do not create up a complicated story. Means it will help you to avoid a big tear scene.
Another and a good idea is the right time to resolve your problem but be honest and sensitive.
While breaking up with someone do not get so angry be relax.