Another common testimony that happens though is the calling-mony, where a person stands in testimony meeting and talks about how important [insert stewardship] is. For example, the temple committee chair may talk about how they have been blessed by temple work or the ward mission leader might share an experience they had sharing the Gospel. Maybe the ward clerk will mention how MLS has changed their life. (Though as far as I understand, MLS is primarily a good tool for teaching long-suffering with an emphasis on the suffering part.) This past Suday, we had three people give calling-monies.
At first, I thought it seemed a little funny and insincere. If you are just sharing to encourage people to do their home teaching then maybe you are not sharing because you are moved by the spirit. Then again, if your assignment at church involves a certain aspect of the Gospel, I imagine you are more likely to have spiritual experiences associated with that aspect, and testimony meeting seems like a perfectly reasonable place to share how your testimony is developing.
Also, many callings in the church are associated with encouraging other people to improve their lives and serve others, and the particular testimonies shared this past Sunday were both humble and powerful. Their thoughts were actually highly motivating to change the way I live my life, and therefore they were appropriate and appreciated.
However, I don't think this is always the case. Clearly, testimony meeting is a time to share our personal convictions. I think it is also generally accepted that it is not a time to just talk about how much we love our friends or talk about or recent trip to [jealousy-inducing vacation spot/Church-history tour]. What is OK then for a testimony meeting in terms of content and motivation?