Here's a sort of ten commandments that I've developed over the years. They might not all apply to everyone, all the time. They're not in any particular order.
1, Go to class. We all have times when the idea of going to class is awful. Maybe you're sick, maybe you're sore from the previous day. Sometimes you have a gazillion things to do. But if there's any way to do so, you should go to your class. Consistency pays off, and there's something to be gained from disciplining yourself.
2. Keep your gear in your car. The medieval sword fighting is rather gear intensive, a full suit of armor, a shield, and one or more weapons. Chances are good if that stuff isn't in my car before I leave home for the day, I'm not going to make it to practice. Or if I do, I lose 20 minutes of time driving home to pick it up.
3. Be the first one to get there, and the last to leave. We've all seen that person who is late to class/his workout, then takes 30 minutes to get ready, then spends like 10 minutes doing the activity before they start packing up to head out. Don't be that person.
4. Eat for what you did, not what you're gonna do. (This one is sort of weight management/nutrition tip....) It never fails. On the days I mean to get in a heavy, arduous leg day, I will up my calories a LOT. Then, Something happens and I don't make it to the gym, or my time there isn't as long or whatever. Those extra calories get stored rather than utilized.
5. Write it down: For resistance training, keeping a record is VITAL. You'll forget how much weight you used in an exercise, or how many times you did it, etc. It's also highly informative to go back through, years later, and see your progress, and mistakes! For non weight-lifitng purposes, keeping a workout journal helps you remember new material, and makes you think about what you did in class.
6. Build Community, not just muscle. When I take classes at the studio, or anywhere else, I am known for going around and high fiving people during pauses. I try to get everyone in the room at least once. These people can be friends, tribe and family if you let them. You can draw inspiration from them, as well as healthy competition. You never know, your sweaty, tired high five might be the pick me up they need to get through the class.
7. No whining. When we give voice to our discomforts we reinforce them. It also tends to bring the overall energy of the group down. Chances are good everyone is feeling the same thing. Suffer quietly.
8. Listen to everyone (But keep that salt shaker handy). I never met someone I couldn't learn something from. People with more experience often have tips and tricks. New folks make mistakes that can be highly educational. and EVERYONE has a different viewpoint. Listen to what they say. You don't have to act on it, or even validate it. It's sort of like panning for gold. Eventually it pays off.
9. Have a Plan. This is particularly important in the weight room. (If you're working with a trainer, or taking a class, your plan is likely already taken care of....). Time is precious, don't waste it wandering around trying to figure out what to do next. On the flip side, don't be so attached to your plan that it paralyzes you.
10. Do stuff you're not already good at.