Slides should have short titles. A long title shows something is wrong.
Use uniform capitalization rules.
All the text on one slide should have the same structure (e.g. complete phrases, idea only, etc.).
Put very little text on a slide; avoid text completely if you can. Put no more than one idea per slide (i.e. all bullets should refer to the same thing). If you have lots of text, people will read it faster than you present, and will not pay attention to what you say.