Some specific techniques that may help:
- foreplay, ideally oral sex producing one or more orgasms
This technique creates lubrication, places the focus on her pleasure first, and most importantly the orgasm produces endorphins along with smooth muscle relaxation in the walls of her vagina
- female-superior positions
Allowing her to be on top lets her control penetration, both depth and rate at which depth of penetration increases. As she relaxes, breathes and becomes more aroused, she'll typically allow the depth of penetration to increase. Personally I find it incredibly erotic to have her on top, facing either direction... it is very, very hot to watch your cock slide in and out of your aroused partner, and this provides the best view.
Some closing thoughts: Most women do not enjoy contact of a thrusting cock-head against their cervix - they find it painful. A woman with a shallow vaginal barrel, a tipped uterus or similar anatomical features will have more difficulty with a partner who's cock is large (lengthwise). Given this, female-superior positions are even more key to a pleasureable vs. painful experience.
I am attracted to petite women, 4'11" - 5'2" range are where almost all of my partners have fallen. Correspondingly, they've been small-framed, in the range of 88 lbs. - 115 lbs. Anatomically, this is a pretty small woman. I am 6'1" tall, 195 lbs., and about 9"x8.5" erect. This is somewhat a size mis-match between me and my partners. I've had to develop technique and expertise to deal with this mis-match over the years. The oral sex to orgasm is one of the best first steps to making it good for her. Once you've done that work, she'll be in the mood to go for a ride and do the rest of the work herself.
