Bill, when I do a seminar I do what the word means. I talk to and inform the people attending. I do not do slide shows or power points for the most part. I have at a few where the crowds were large like at the Mass Maritime for example but it is the spoken word mostly.
I do bring a few props. I find people really like to see what I use for gear and lures and I show them. I go to seminars to learmn something not view pics or here how many we caught this night or that. I want to know the reason you caught this many or that many that's where the real value of the talk is.
One thing I have learned is that there are so many ways to trick a bass and so many things to learn that to make the bulk of your talk a picture show is really not fair to the crowd. People want to learn how to be better fishermen and fisherwomen. Tell them how to do it, not where and when but how and they can do the rest.
Put up a picture/story board with photos as a backdrop/display and invite the crowd to come up to introduce themselves after and ask a few more questions and take a close look at your stuff. They love that and so do I. And lastly don't let a single criticism detract you from realizing that the majority of folks enjoyed your talk.
Hope this helps
