A vote of thanks is a short (2-3 minutes) expression of thanks to a speaker on behalf of the audience. Therefore it is not another speech, nor is it an evaluation, nor should it repeat the Chairman's introduction of the speaker, nor may it be prepared in detail in advance - all will become clear.
The opening sentence (which may be prepared!) might be of the following nature:
"Mr Chairman, Ladies and Gentlemen! On behalf of Norwich Orators, I am very happy to thank Fred for giving his speech on 'Promotion in the Mexican Navy' to us this evening..."
and the concluding sentence might be along the following lines:
"So, Mr Chairman, I say, once again, that we are all most grateful to Fred and I now ask the audience to express its appreciation in the usual way."
[Please note that they will be applauding the speaker (Fred) and not the proposer of the Vote of Thanks.]
With experience, the opening and closing formula may be modified, always provided that the principles that they embody are not forsaken.
Needless to say, the person proposing A Vote of thanks will listen most carefully to the speech. The proposer should pick out two or three points that s/he and/or the audience found particularly interesting and, in the vote of thanks, refer and respond to these. However, the proposer should NOT repeat those parts of the speech, nor discuss whether s/he agrees or disagrees with them, nor enter into any kind of debate.
With practice, how to select some useful or illuminating points, and how to incorporate references to them in the vote of thanks, becomes easier and, with time, the proposer will produce a presentation that resembles an excellent dessert following - and in happy harmony with - a fine main course.
For the moment, consider these extracts from a hypothetical vote of thanks to Fred and decide which (if any) you consider suitable in the light of the above discussion:
Fred's mention of pocket battleships reminds me of an incident during the Korean War. My uncle was on Dog Watch in the Straights of Malacca. It was a dark and stormy night...;
I was particularly impressed by Fred's tale of how Commodore Sanchez was twice passed over for promotion because of his terrible table manners.
Fred sometimes talks so quickly that we have no time to think through the implications of the very interesting but often complicated point that he is making.
I have to say that I disagree with him fundamentally regarding the role of Mexico in the American Civil War.
I have to say that, along with everyone else present, I was completely enrapt by his consideration of the role of Mexico in the American Civil War.
Fred's tale of Ensign Gonzales and the attempted mutiny on board MNS Arrogant reminded us all, I sense, of Shakespeare's reference to "vaulting ambition which o'erleaps itself".