One of my favorite parts for a Toastmasters club is the evaluation - every prepared speech gets an evaluator. That way, as a speaker, you get to learn what to improve; as an evaluator, you get to learn how to give other people feedback in a way that's constructive and positive.
I didn't know how to evaluate when I joined Toastmasters. I gave several speeches but I never dared to try giving an evaluation to other speaker. I worried that I could not gather enough points to talk about; I worried that I would be too harsh in my comments. I didn't know how to evaluate, or what makes an effective evaluation.
After about a year, I joined a seminar in the Toastmasters Leadership Institute (TLI). It was about making effective evaluations. I was sooo happy that I went to that seminar, because it gave me the courage to stand on stage and give other evaluations.
Here are some key points on how to effectively evaluate a Toastmasters speech (and other speeches):
1 - Capture the exact opening and closing sentences.
2 - Capture key points that the speaker used to develop the speech.
3 - Observe how the speaker used speech delivery techniques, such as vocal variety, hand gestures, eye contact and footwalk.
4 - Make notes on what each of these was done well and which needed improvement. Note down how to improve.
5 - When evaluate on stage, pick two or three most outstanding aspects and compliment; pick two or three aspects that can be improved and talk about how to improve. Do not try to squeeze every comment into the evaluation - you only have 3 minutes. There are plenty of opportunities to talk with the speaker offline.
6 - Practice evaluting speaker by taking notes at every speech in your Toastmasters meetings. Your hard work will pay off.