From the woman I have been with asking questions like this, and getting straightforward answers thought I'd help:
Sadly (for guys at least) it's not quite as easy as one stroke pressure/speed and lubrication to have an cllmax.
Just like breast sizes, and heights of woman's attractiveness to guys, there isn't a universal size/shape that appeals to everyone, as vagina's come in different sizes as well, and cllmaxs (clitoral and vaginal) come in different flavors, where the stimulation of one/both have just as much to do with the position and motion as size. Vaginal cllmaxs are heightened from the walls of the channels being pressed, and sensitivity generally decreases getting deeper, and hitting the uterous isn't pleasurable at all, so within reason thickness is more important to length for this aspect. Vaginas are pretty flexible and accomodating...remember they have to adjust to pushing out the large head of a newborn child!
Oral for woman (depending on the person) can be either greater or less pleasurable, depending on technique. Overall clitoral stimulation is higher orally, but this can also be done with hand/fingers, or in some positions via the pelvis. As previous Clitoral and vaginal cllmaxs differ in 'flavor' perhaps like the difference between chocolate and vanilla, good by themselves or together.
Not all of cllmax's for women is just the physical act (as it is for guys), much of it takes getting them in the right frame of mind...which is unique to each woman. Some can have one with just focusing on a thought -without stiumlation! For some they can have one (or several) within the space of a few spontanenous minutes, for others it takes a whole evening (dinner, walking, etc) to truly get into the mode.