Finding a good mikvah attendant is like finding a good therapist.
I'm not joking in the least. Not everyone clicks with the first therapist suggested to them. Suddenly, they happen across that one therapist with a golden tongue, the ones whose words are gems of wisdom, and hope suddenly appears on the horizon.
Here's one of those tidbits of useful information they don't teach you in kallah classes- you will simply not mesh with every mikvah attendant that you meet. Their personalities, ages, stringencies and qualifications will vary and thus you will feel more or less comfortable with each of them. The problem is that if you're not aware of this, you may end up feeling that you hate the mitzvah of Mikvah and all the attendant Niddah laws when in fact, it's not the mitzvah you hate but simply the experience you are having.
The aesthetics of the mikvah may be important to you as well. I know they are to me. I hate cramped rooms where I feel that I can barely breathe or move. I love spacious rooms. And I love rooms that are visually pleasing, with baths made of marble and floors of beautiful opal-colored tile. But then there's the flip side. Some mikvaot will provide you with anything you could possibly need in copious quantities- toothpaste, toothbrushes, shampoo, bars of soap, rubbing alcohol, cotton balls, nail clippers, razors, eye-makeup remove and suchlike. Others only offer them in little disposable packets. I have to decide what is more important to me- would I rather have a spacious room with little packets or a less spacious room where I don't worry about exhausting the shampoo supply?
Another question is whether your mikvah will be physically accessible to you. It may be that the mikvaot I have been to have a special section for those who are elderly or physically handicapped. If not, however, there are places I would specifically tell such people never to go because the simple process of stepping into the bathtub would be impossible for them. Rather than having steps leading down to a bathtub or a low bathtub, the baths are so high that one must agilely swing one leg over while carefully balancing on the other and holding on to the silver door handle with an iron grip.
Back to the attendants. I cannot stress how important it is that you feel comfortable with your mivkah attendant. It might even be worthwhile to travel to a mikvah that geographically is farther away if it means that you are happier with the person who escorts you and/or the amenities there. One important factor is age. Some people feel more comfortable with older, experienced mikvah ladies who are already grandmothers. These people figure these women have seen it all and are nurturing, maternal figures who help them along. In contrast, there are those of us who specifically want younger mikvah ladies. We can relate to them more easily, feel more at home with them. Their youth, sweetness and friendliness may be comforting.
Sometimes mikvah attendants don't mean to make you feel uncomfortable and yet they manage to do so anyway. One woman told me that the number of times I dipped was the most she had ever heard of, which made me feel very uncomfortable, as though I were taking up her time. A different woman made sure to put me at my ease and laughed blithely, telling me that she has had women come to the mikvah to dip 52 or 330 times as a segulah. Needless to say, that made me feel a lot better about taking up her time, since compared to that, my tevilah was nothing.
Some mikvah ladies are also very strict and manage to make you feel bad about your preparation if you accidentally forgot to do something. They mean to be helpful when they suggest that you should bring your checklist to the mikvah, for example (most mivkaot have checklists in the rooms anyway, for that matter), but in truth they just make you feel incompetent. Then there are other ladies who make it seem like a fun game: oh, there's just this little speck of dirt, let's see if we can get at it. You're involved in the process rather than being the incompetent person who is causing problems by not having noticed that little particle.
In short, definitely try out different mikvaot and different mikvah attendants- like all people, you probably have a particular style, age bracket and personality with which you mesh best. Take the time to try to find that person- it can really enhance your experience when you do. And if you have any questions about mikvah or if you would like advice regarding where you can find one if you're interested in starting to keep this mitzvah, as always, feel free to ask me.