The most effective way from my experience, being a technology coordinator for about 6 years now, is to have 1:1 sessions with teacher who is not integrating technology and try to suggest some easy technology that they may use in their class. I have also done professional development session on ISTE standards for both TEACHERS and STUDENTS. The problem is that some teachers are really scared of using the technology if they don't know it. As a technology coordinator I always try to explain to teachers that they are not required to know the technology in and out. They just need to know what that tools can do and then let their students to use it. I also like to share students work and that usually lead to positive reaction and most of the time teachers will stop by asking about how they can do something similar!!
I think motivation comes first and then gradually by not feeling them overburdened because working with technology requires a lot of research to pick the best suited technology