Dubb your correct about hands on, but don't casually dismiss seminars, education, or certifications. Knowing the basics of the technical and engineering aspects of wall building are VERY important. If you don't know the why behind what your hands are doing then chances are your walls may fail. As far as learning from on the job with "experienced" landscapers, that only works if they do the job correctly! For example, a local large LCO built a wall here on Peach Street. Not positive on height and width, but its long and not very high, maybe 4-5 ft. The wall is about 3 years old and it is failing. I knew it would fail because of the way they built it. I don't have all the specs on the wall and wasn't there for all the construction, so the reasons I'm going to give for failure are based on what I could see from the road. The first big clue they wern't building it correctly was the excavation behind the wall. The excavation was only about 2ft behind the wall. With the height of the wall and the slope above, its my opinion there should have been geogrid in that wall. With the excavation being so short I'm fairly sure there wasn't any. I'm thinking with the slope and height of the wall, excavation would have been around ten ft behind the wall. Again, I wasn't there and I'm not an engineer, but with what I've learned about the technical and engineering aspects of wall building, I was sure it would fail. I agree hands on is very important to hone your skills. Thats why I suggest the first dozen projects be small. While honing your skills on small projects, the mistakes you make will less likely cause failures. Education is a powerful tool in the tool box!