I haven't had a full-grown pubic hair since 1982. There have been a few instances with maybe 1/4" growth because of long backpacking trips or the like, but that is it. My secrets to no ingrown hairs and itching? Wow, wouldn't laser hair removal be nice, but too pricey.
1. Use your choice of shaving cream, but I use plain old bath soap while in the shower.
2. Trim as close as possible with a scissors or that pop-up gizmo on an electric razor.
3. Always shave WITH the direction the hair is growing, never against it. For me that is to shave towards the penis/testicles. Where my legs connect to the pelvic region I shave away from the pelvis region.
4. Use a good body lotion, such as Lubriderm when dried off.
5. You can always use a special electric razor such as 'Cleancut' made by a French outfit in Japan called 'Seikos-Yard Co. Ltd.'. This you shave against the grain and use baby-powder, but still use the Lubriderm when finished.