The tricky part of boundaries is not always in the setting of them, but the sticking to them. Boundaries are those imaginary lines in the sand that we draw to help protect ourselves from harm, both physical and emotional. Setting good boundaries can help you lead a happier, healthy and more productive life.
Setting boundaries needs to begin with a full understanding of where you are at emotionally. Take stock of how you're feeling and what things are most important to you. Ask yourself questions like, "Can I negotiate on this point?" -- if the question is a sound "absolutely not," then you're on your way to building a boundary. Consider what your limits are and what your bare minimums are to be happy and healthy.
Be Selfish If Need Be
Being selfish gets a bad rap sometimes. However, it's not always a bad thing when you consider it in the larger context of self-preservation. Give yourself permission to be selfish about the things that are most important to you. For example, if you need more autonomy in your relationship, set days or times aside where you will do something without your partner. Stress to him that you expect to be left alone during that time. When setting boundaries it's okay to put a fine point on what you will and will not accept as behavior from other people. Being a little selfish some of the time can free you up to be much more giving the majority of the time.
Have a Strong Resolve
Setting a boundary is only as good as your commitment to it. Once you've given yourself or another person a rule about how you will be treated or what behavior you will tolerate, you must stick to it. For instance, if you need to get through your work day without being bombarded with text messages from your partner, tell him so and then stick to it. Ignore his messages if they come in, and at the end of the day remind him that you asked him not to message you during business hours. This may mean occasionally stepping back from a relationship to practice healthy self-care. If you feel like your boundaries are being tested, spend some time alone to take care of yourself and it will help reinforce your resolve to keep that boundary firm.
Ultimately setting a boundary with a man is going to mean being very clear in what your expectations are. People aren't mind readers, so to get the most out of boundary building, be concise. Tell him you're setting a boundary, stating exactly, in no uncertain terms, what you expect and what you're hoping to gain from having this boundary. If you're setting a boundary that will help your relationship, explain how it will do so. For example, if the "no texting during business hours" boundary is something that is important to you, explain that it will help you be more productive at work and therefore less stressed when you're off work and spending time with him. This will enable you to focus more on your relationship when you're with him instead of splitting your attention. It will help him respect your "line in the sand" and it will make it easier for you to stick to it if you've been explicit from the get go.