Setting your reactive dog up for success in training class

Mr. N's last training workshop was horrible. His tail hung limply down for a good portion of the workshop (we call it sad tail in our household), and  he refused to eat even his favorite things and towards the end, he bolted inside his carrier and stayed there. And he was extremely reactive towards the other dogs. 

We had a fracas with another dog there previously and I think he remembered that especially because it made me extremely stressed and he feeds off my stress.

Mr. N was not very enthused about class previously

So I was concerned about this week's workshop so I tried to put some things into action that might help him be more successful.  He was very good and aside from a little barking at the beginning when everyone came in, he settled down quickly. And his tail was up all class. These are some of the things I tried. 

• Bring your dog's "crack." Mr. N loves cheese and meat. He will not work for dry treats and vegetables and fruit even at home so at class, they wouldn't even merit a glance. So bring whatever your dog loves and will do back flips for it. I would totally bring a squirrel or a rat if I could figure out the logistics and it wouldn't be cruel to the other animal! He also loves soft, animal-shaped toys that other dogs have played with. 
• And try swapping treats. Mr. N was starting to get bored with his turkey and cheese so I borrowed some meatballs and he was all about that. 
• Give your dog something to do. We're still working on mat work but regardless, Mr. N would not sit still for the bulk of two hours anyway. So if it's not our turn to work, we practice quiet things in a corner. We do some shaping with objects, "find it" with food, targeting and run through his tricks. 
• Bring some chews or a stuffed Kong. Mr. N gets too hyped up to chew calmly but I've seen that work for some dogs.
• Watch your dog. Do you know what stress signals your dog exhibits? If I interrupt Mr. N before he goes over threshold, I can usually redirect him. 
• Watch the other dogs. Are they being rude? Is your dog reacting to their behavior? Mr. N thinks hard staring is very rude and will tell the dog off if I don't notice it first and reward him for not reacting. 
• Know your dog's limits. Take your dog out if he needs a break. I bring Mr. N's soft carrier with me so he has a place to retreat to if he is overwhelmed. 
•  Good positioning. Mr. N does best with one particular dog so I asked the instructor if we could sit next to her. Away from the doors and windows is also preferable. Less stimulation.
• Talk to the instructor. After the fracas, I talked to the instructor about my concerns and she implemented more stringent measures. We have more visual barriers in class (the dogs can still see through them but it's a visual reminder), and people were reminded about keeping their dog under control and giving other dogs space.

What steps do you take to make sure your dog is successful in class or in life?