Use variation and reward to keep your students' attention.
Suppose you regularly have your students count from 1 to 30 each day.
After about three days of using that activity your students will start to
get bored.
It is very simple to spice things up by providing small rewards or treats
from time to time.
You could choose a number from 1 to 30 and write it on a paper and tape that
paper to a shiny new pen or pencil (that you bought in bulk right after the
"back to school sales" turned into "clearance sales.")
Then at the beginning of the activity announce that you will be giving away
your shiny new pen to one of the students who happens to get the lucky
number.
Next you ask any student to pick another student at random. Have the
randomly picked student show the number 1. The student to the right does the
number 2, and so forth until you get to 30.
Finally, you announce the secret number (in sign language) and ask who was
"that number" as we went around the circle.
The lucky winner raises his or her hand and you bestow upon them the prize.
The next time you use this trick you can vary it a bit by requiring the
"winning student" to accurately show you all 30 numbers.
If the student screws up, you can give them the opportunity to try again
(showing you all 30 numbers) at the beginning of the next class session.
Thus they will feel inspired to go home and practice (instead of feeling
robbed).