In my opinion the two most important details in giving a great massage are attention (having your full attention on the client) and intention (intending healing and/or giving a great massage). A massage therapist who practices the mindfulness of attention and intention are much more likely to give a great healing massage than a massage therapist who doesn't practice mindfulness; regardless of the amount of training or experience.
Twenty years ago, when in massage school, I learned this lesson experientially. In class they taught us that massage moves lymph, and therefore can speed up healing when ill. Well I got a cold, so I thought a massage would be a good idea. I also thought I needed someone with a lot of experience. I found "Terry" in the phone book, a massage therapist with 15 years experience. The massage felt good, but it was far from great. Why? Because, though "Terry" was proficient, I could feel that he was just going through the motions. He didn't really have his attention on me, and his only intention was to complete the massage and collect his money. Fast forward to a week later. I received a practice massage from a fellow student. Though "Chloe" had nowhere near the training or experience that "Terry" had, she gave me one of the best massages I have ever received to this day. Why? Because from the get go she had her full attention on me with the intention of giving me a great healing massage. It was mindfulness plus, and it was a lesson I'll never forget.
Fast forward to the present. Now I have a lot of training and a ton of experience. Both important factors, but I truly believe my success has more to do with mindfulness. I attempt to bring this into every session - my full attention on my client with the intention of healing and improved health. Experience and training are important, but without mindfulness they could be rendered useless. They say "experience is the greatest teacher", but that is only true if you are mindful of the experience.
Consequently I can honestly say that I learn from every massage I give, as well as from every massage I receive. I practice mindfulness, and your massage therapist should as well. Experientially I learn more from giving and receiving massages than I do from classes, books or videos. In my opinion in choosing a massage therapist I recommend interviewing them first. Ask them about their training, experience and philosophy. In the course of a 5 minute conversation you can get a pretty good idea if a person practices mindfulness.
And a final word of advice, when receiving a massage. If your massage therapist spends the session talking about themselves, answers the phone, leaves the room inexplicably, or you can tell that thery are just not there - then find another massage therapist. Many Blessings and Be Well.