There is nothing worse than being dumped over a text message. It shows minimal effort and is not the best way to leave a relationship. Unless you've only gone out a few times, your ex will want to have a conversation about the situation. Be the bigger person and avoid taking the easy way out. There are exceptions to this rule. If you only went out on one date, there shouldn't be an issue with a text. If you feel unsafe, do not put yourself in a potentially dangerous situation and contact someone you trust.
Even if you are set on breaking up with your boyfriend, it is always important to let them have their turn to speak after you have. It is important not to interrupt them when they are speaking, because it is their feelings, just as you did. Remember to try and remain as calm as possible, even if you don't like what you are hearing. After they have said what they needed to say, you can leave and give each other space.
If you were in a relationship with someone, chances are that you once had strong feelings for them. Being respectful of their feelings when you choose to end things is the best way to make sure you do things the right way. Be honest about how you feel and what has led you to come to this decision. They deserve to know what has happened between the two of you. Be honest while keeping their feelings in mind to make sure nothing gets miscommunicated.