I myself when in a long term relationship I do not use safe words. I do not recommend this for new dominants or new submissives. One reason is your still learning. It was some ten years, into the lifestyle when I dropped the safe word system, with only one exception, that is during a session with a new submissive. Being new I want them to feel safe, them knowing just one word, and everything stops.
Something I want to stress is , if a safe word is called, you stop what you are doing immediately, no questions asked.. If the submissive is bound, you untie, as fast and calm as you can, you want to stay calm, because you want the submissive to stay calm as well.
Once untied, the submissive will most likely be somewhat scared, confused, not really sure what to think. It is your responsibility as a dominant to go into the after care mode. At this point it is very important to hold, and talk to, find out exactly what happened ? what was it that triggered the safe word ? what was it you could of done different? How is the submissive feeling right now ? You want the submissive to feel as comfortable as you can. If you follow these steps chances are the submissive will allow you to repeat the same in the next session, because they feel safe.
Now as dominants we always want to push limits, we want to take the submissive to greater heights, and assisting the submissive to reach sub-space.
During a session it is important for the dominant to stay in control , I am talking emotionally but more so if your doing impact play, you do not want to stray where you hit , a lot of damage can be done and you can cause serious injury if not careful. This includes using the flogger.
Let the submissive choose there safe word or words, If I am working with a new submissive I prefer they pick 3 such as green, yellow, or red. Green means everything is okay, yellow it is beginning to hurt or cause discomfort. Red stop, they have reached there limit , they have had enough. It is important that you abide by these words, if you do not stop, one that is clear abuse, and two you will probably never get another chance at play again.
I cannot stress enough, during a session it is important to talk to, ask how there feeling? are they okay ?
I can assure you if you follow these steps, even if not in a long term relationship, you will get plenty of play, and you will become a respectable dominant with in the community.
If you do not follow these simple rules, all it takes is for you to hurt someone one time and you as a dominant are done, finished. It could take months or years to regain that trust.
Respect the submissive.