These notes a from Calling Notes for Irish Dances, a brochure that had in print from late 2009 through 2019. I still have a few copies of it floating around.
MacKenzie's Tips for Callers
Think ahead. Your mind should be 8 bars ahead of your body.
Call early. Most dancers need at least two bars to understand a call.
Call often. Don't give more than 16 bars of movement at once.
Be loud. It's called "calling" for a reason.
Know the dance or figure. Ideally, you will be able to dance whatever you're calling from any position in the set.
Know your dancers. If you haven't danced with your set before, find out what dances and figures they know.
Know what you're calling as well as your dancers (or better). Think about timing, location, and other details.
Walk it. If you have time before a dance begins, walk through tricky figures.
Help out newer dancers. If you see someone struggling, call in more detail.
Be patient. Sets break. One of the most important calls is "Everybody go home."
Try again. If a figure doesn't crash but doesn't look nice either, give the dancers another chance to get it right.
Pay attention. If a dancer says they don't recognize a call, you can change it or call the figure in detail.
Tell the musicians when you're done. Try calling "lead around" (16-bar warning) or "siné" (8-bar warning).
Clap for the musicians. It's only polite.
Practice. Calling is a learned skill.
Have fun!
These tips are an ideal. Not every tip is applicable for every dance or polka set. For example, the Bluetooth speaker doesn't much care when you're done dancing.