A few points occur to me (mainly from a band's perspective)

A caller needs to judge the ability of the dancers and tailor both the programme and how the explain the dances accordingly. However even novice dancers like to be pushed a little, and can get a real sense of achievement from managing a dance that they would have found too difficult at the start. It takes judgement and experience to get that right.

A caller doesn't just call dances, and also needs to get the 'tone' right when speaking to the audience. This is nothing to do with their dancing ability, it's about the make-up of the audience and what level of banter they'll respond to. What works brilliantly with one audience might offend another.

Tell the band without prompting what type of tune is needed and perhaps a bit of information about the dance, to help them choose a suitable set. "Oh, 32 bars of anything" isn't very helpful, but even if you're told it's a jig or a hornpipe, tunes have their own characteristics and internal rhythms and some tunes go better with a particular dance than others.

Tell the band how many times through the dance, and agree a signal for 'last time' - some bands like to know 2 or even 3 times ahead so they can wind the tune up (or down) to a planned musical finale.

Be prepared to take responsibility for the evening and make difficult decisions. I have seen a caller call a halt to an entire evening's dancing on health and safety grounds (only once in 30 years) - it takes a bit of guts when the customers have paid and are enjoying themselves, but it was the right thing to do.