Explaining tasks in the target language

Some of the teachers I have come in contact with have trouble deciding if they should explain tasks in English to save time and have all students on board(as I did when I started teaching!). My advice usually is to give more detail when you are demonstrating (you can use 2 puppets or 2 students who actually do what you want them to do in front of the class); to persevere: if they don't get it, try it again in Spanish in a different way until they get it; and finally to take care of those that you see did not understand and help them individually while the class is performing the task. 

I recorded a video of me explaining a task in second grade: I wanted them to work with a partner and have each other guess who in the class was wearing an article of clothing. Explaining it in English would have taken me 30 seconds, but it can be done in Spanish. This is how I did it: I showed them a video I had made with my daughter asking questions about some kids in a picture and then I asked them to talk to each other. I had to correct a few (usually the ones who don't pay attention), but everybody accomplished the task.