As a general rule of thumb, I like the 10/20/30 rule: 10 slides, 20 minutes, 30pt font. I'm not a fan of speaking (although I'm starting to come round to it) a

As a general rule of thumb, I like the 10/20/30 rule: 10 slides, 20 minutes, 30pt font. I'm not a fan of speaking (although I'm starting to come round to it) and I tend to waffle both on the slides and when talking, so this helps me to keep focused.