Many guys, myself included, come to regard missionary as the boring sex position. But I have learned that missionary is the easiest way to make her cvm. Sex is a dance that begins when you are hanging out with her, not once you get naked. Jitterbug has it right - "make her laugh, make her think, make her cvm." If there is a formula, it would read like
Psychological Stimulation/Kino-Foreplay-Oral-F her
Tongue that pvssy good, then fvck her missionary first. Once you open her up for a lil bit, reach down with your left and rub her cl!t with the pad of your middle finger while you are fvcking her. A circular finger motion with rapid directional changes will encite and entice her to forget about the guy at work.