Act it Out
As you explain, act it out so students can see with their eyes what you want them to do.
Are you asking them to take out a pencil? Take one out too.
Are students allowed to walk around the room during the assignment? As you explain expectations, walk around the room showing them what they would be doing.
Visuals
Create a slidedeck or anchor chart to demonstrate and remind studenst of expectations.
Non-Examples
Pair non-examples with examples to weed out miscommunication.
Watch your non-verbal cues. Don't nod your head yes while asking a rhetorical question with a no answer.
For example, "Class, should we be putting answers in this first section?" The class says, "No," but the newcomer saw the teacher point to the section and nod their head yes. Is that why my newcomer is doing the opposite of what I say?
Concrete Connections
Attach a concrete reward to difficult behaviors to explain. Award points for desirable behaviors that are hard to explain.
When their points add up to a reward, they will start to put the connections together.
Secondary tip: reward minutes on a cell phone.
Elementary tip: Give them a skittle or goldfish cracker for each tally.
At first they won't understand why but it doesn't take long for them to figure it out.