Please feel free to apply any gender identity or number of people to this piece of writing. I originally wrote it for a group of mostly female identifying subs into male identifying doms, and that tends to be my orientation as well, but it applies to everyone. :}
So, what are the signs that you are dealing with a good dominant?
There are many kinds of dynamics out there, and what might OUTWARDLY look healthy or unhealthy might not always be the case. When you are involved yourself, you need to decide what works for you in a healthy fashion.
1. He listens to you and respects you. He gives you a space to express yourself honestly about how you feel, how the dynamic is working for you, what isn't working, what's good and what isn't good. If you tell him something is a hard limit, he doesn't cross it. If something you normally do isn't ok for whatever reason that day, he respects it. Unless you have negotiated otherwise, he gives you time to ask for things, without shutting you down or attacking you for expressing yourself. He encourages and supports you in expressing your wants and needs, and actively letting him know what is good and what feels harmful to you. He recognizes that you know yourself in ways he can't, because no matter how good of a dom he is, he hasn't lived your life as you, and he cannot really see inside of your head, even if he's amazing at reading you.
2. Even if you are engaging in thrilling, edgy, "scary," play, he consistently shows that you are safe with him. He proves, through consistent actions and attitude, that he is safe to be with, and to let go with. You feel secure with him, in a good way.
3. He makes sure he knows what your health issues are. He makes sure he knows what your triggers are, if you have any past trauma. If you hit an unexpected landmine together, he does his best to not take it personally, and instead works to make sure you feel safe and ok. He will give you whatever care you need, and talk it out with you. He may even be willing to try to work through the trauma with you, if you both want to, but he also will recognize that he isn't a licensed therapist. Unless, ya know, he actually is. He takes these things seriously.
4. He encourages you in pursuing your own passions, in making your life better, in being a happy, healthy, empowered person. He doesn't try to take over every aspect of your life unless you want him to. He recognizes that you are a whole human being, and that things in your life that do not involve him are also important. He makes sure you have time for your hobbies, for your friends and your family, and he doesn't begrudge these things. Being with him makes your world bigger, not smaller.
5. He admits when he doesn't know something. He is confident, not arrogant. He doesn't pretend to be good at something he has no skill, experience, or training in, especially when trying it could endanger you, or him.
6. He takes the time to learn how to do the things you agree to do together, so that they are done well, and safely. Your well-being is important to him.
7. He also strives for balance in his own life. He takes care of himself well enough. He works hard at having his shit pretty much together. Nobody is perfect. He might be poor, he might be well-off, he might be healthy or he might have chronic illness or a disability, but he isn't living a life of perpetual self-fulfilling prophecies of victimhood. He takes personal responsibility for the things he does and doesn't do. He can take care of things in his own life, which gives you confidence that he can take care of you to the degree that the two of you agree to. This includes accepting help when he needs it- that is an important aspect of self-care.
8. When he fucks up- and he will- he takes responsibility for his part. He works to make things right. He works to not fuck up like that again. He seeks to learn from his mistakes, grow from them, and do better. He expects the same from you, and has compassion for himself as well as you for fuckups.
9. He is willing and able to set boundaries for himself, for his own safety, and for your safety as well. Up to and including ending a relationship which has been toxic, in the healthiest way possible. He not only recognizes that you are a complete human being, but that he is, as well.
10. He really works to learn you, find out what puts you into subspace, what really works, what turns you on if you have that kind of dynamic. He doesn't assume that because he is Lord Master Domlypants the III, that he knows you better than yourself. He recognizes that what works for each submissive is different. That every dynamic is different. That what works in that dynamic may shift from day to day. Hormone cycles, health, external stimulation and life situations, all of these make a difference in how play will go, what what will work and not work. He is flexible, always willing to learn.
11. He checks in regularly. Out of scene, and in scene. This doesn't mean he has to break the scene, bring everything to a halt, pull you out of subspace. He checks in, though. Finds out where you are at. Makes sure things are ok. Makes sure both of your needs are being met. When they aren't, it can cause resentment to build over time. He makes sure that you and he are on the same page as far as expectations are concerned.
12. He's good to the people around him. He treats service industry workers with respect. He shows empathy and compassion, even if in scene he is a big nasty mean scary sadist because that's what you both love and crave.
13. He is consistent. Even if you both love him keeping you on your toes, it's done in a way that is ultimately healthy and confidence-boosting. You know you will be safe. You know you can trust him. Consequences and punishments, if they are there, are not going to cause you lasting harm. This goes along with that whole building trust thing. Once you are deeply involved, he continues to be trustworthy. He continues to be respectful. He continues to be a positive force in your life. He continues to make your world bigger. You might do scary stuff, but he doesn't terrify you. You continue to feel safe to let him know if something is wrong, and let him know when something's great, too. You continue to find more joy than bad, by far. His true colors are what he first showed you, only deeper, more vibrant and bright and beautiful.
14. When you think of him, you don't find yourself making a bunch of excuses for his bad behavior. You don't cringe internally and feel like you are walking on eggshells. Instead, you get a nice warm feeling. Joy. Peace. A thrill. But good stuff. Happy stuff. You feel fulfilled. You feel safe. You feel excited. All kinds of things... but the good vastly outweighs the bad.
15. If he is in the community, he has earned the respect of at least most of the people there. Interpersonal conflicts can happen, yeah. But he has earned respect and trust by his actions, not with just charisma, or a cool house he throws fun parties at, or because he looks hot. There aren't a bunch of people saying "you really have to watch out for that guy. He's not ok." He's able and willing, if he isn't brand new to the scene, to provide references. He doesn't get pissy at you about asking around about him. He thinks it's a great idea, in fact!
16. He supports you in taking whatever safety precautions you see fit, and encourages you in it. He may even ask, in the beginning, "does someone know where you are going? Have you set up a safe call? Please do so, it'll make us both feel safer, and your safety and feeling ok is important to me."
17. If you are bound, he checks your circulation regularly. If you are being flogged, he's careful of your aim, and if he's hitting a bad spot, he takes your feedback seriously and adjusts accordingly. If you cry, he makes sure it's a good thing.
18. He doesn't punish you for having emotions. He is supportive. He might work to help you to do better, to get through things, to grow stronger, but he is TRULY doing so, not bullying you into shutting down and disassociating.
19. Bad scenes can happen, but for the most part, you look back at your play together and think, "damn, that was amazing. That was awesome. I loved that. That made me happy. I'm gonna be thinking about that one for a while." He makes you want to please him, and you know he'll also want you to be happy and fulfilled- and he shows it by making that happen, too!
20. If he says or does something that upsets you, he works to see it from your perspective as well, instead of instantly going on the defensive and attacking you for reacting poorly. Maybe it came off wrong, maybe he didn't do anything wrong, or maybe what he said or did was offensive or hurtful in a way he didn't consider, but he chooses to work it out. Of course, this means that you must also do the same for him!