There are a lot of noes on the road to "I do." When dating, it is important to recognize early on who is and who isn't a good fit for you. The more skilled you become at compassionately turning potentially poor mates into potentially great friends (or distant memories), the more drama-free your life will be.
Listen to your instincts. If it doesn't feel right, it doesn't feel right. Don't waste your time trying to fit a round peg into a square hole. Relationships are worth working for later on down the line, not at the start. Chances are if it doesn't feel right in the beginning, it will never be right.
Don't hesitate. Sooner is better than later. Once you know there isn't good potential for the two of you, let the other person know and let it go. The quick, clean cut is the least painful.
Break up in person if at all possible. A phone break up can be acceptable if you can't make arrangements to see the other person for some time or if you have been seeing them once a week or so for less than a month. If you have been dating more than a month, have seen each other two or three times a week within the first month or have been sexually active with each other, you really do owe them the sincerity and compassion of a face-to-face break up. Never break up over text, email or a social network.
Be direct and honest. If the simple truth is you don't feel that you and the other person are a good fit, then tell them so. Don't give mixed messages such as, "Maybe it will work in the future," and don't offer platitudes such as, "it's not you, it's me."
Own your decision. Don't act disinterested or unavailable in the hopes they'll "get the message." It is far more cruel to leave someone hanging than to let them down gently. Don't put responsibility for your decision on God or your mother or your ex. You don't have to justify or apologize for thinking someone is not a good fit for you, but you do owe it to the other person to tell them honestly and directly how you feel.
Keep it short and sweet. The less said the better. It is okay to answer the other person's questions if you can answer them in a way that is not hurtful, but don't let the other person badger you for explanations. If they try, simply repeat that you are indeed sorry but it's just not working for you. Do not allow yourself to get pulled into a counseling session or a debate about whether they can change for you or whether you should give them another chance.
It is painful when someone breaks up with you. Don't make it more painful by being cruel or insulting. Focus on how you feel, not on the other person's faults. Never engage in a tit-for-tat debate over your qualities or theirs. Remain civil and kind, and remember the advice your grandmother probably told you as a child: "If you can't say something nice, don't say anything." If you can say something nice, by all means do.
Role-play the break up conversation with a friend. Ask your friend to act out several different responses, including hostility, disbelief, hurt and silence. Role-playing is a great way to ensure you remain calm, cool, collected and kind no matter how the other person reacts.