Since there are many guides, tips, and tricks to giving a scientific talk , here are a few links to other scientists' guides and thoughts.
"Seminar on Seminars: How to Give a Talk" Kenneth Suslick
"Non Talk on Giving Talks" Lucianne Walkowicz
"Learning to Give Better Talks" Kelle Cruz
"How to Give a Killer Talk" Chris Crockett
"How to Write a 5 Minute Talk" Julianne Dalcanton
"The 9 Kinds of Physics Seminar" Matthew Rave
Advice on Color Schemes & Templates (also helpful for Figures) by Paul Tol: