Ending a relation is never easy. What can you do to reduce the pain it will cause?

A few tips:
Don’t keep putting it off and don’t beat about the bush. Say it as it is, for instance: “I have something unpleasant to tell you: I want to end our relationship.”
Give a honest but kind explanation. Answer the other’s questions as openly – and diplomatically – as possible, not hurting him or her unnecessary.
Don’t end a relationship through email and don’t do it on the phone. Never use a friend to tell the bad news to your lover.
Don’t tell others about ending your relationship until you have told your partner, thus avoiding the risk of it leaking out.
Don’t do it indirectly, by not contacting your lover as frequently or by starting fights all the time.