Shaving is OK..but there's some problems if you are inconsistent with doing it.
If you get the rash, just treat it topically...I like that Aloe Sunburn Pain Killer jell as it has a local anesthetic in it and the relief is pretty quick.
What the rash means is that somehow you got it wrong.
RULES:
1) HOT WATER TREATMENT....use no detergent soaps which is what most of them are these days. You need a fine castille soap or at the least something like Ivory as they leave no residue. I like to use shampoo to cut the oils...more on that further down.
2) A FRESH RAZOR...I suggest NOT buying those multi-bladed swivel head toys.
3) Use real shaving cream...
not a bar of soap, not baby oil or shampoo..but a real men's shaving cream...and don't go cheap here either. Get a brand name..and look for the sensitive face label if you want.
4) Do NOT shave lying/reclining in the tub in a bath. Stand up in the shower using the hot and moist air in the shower but make sure that you don't allow the water to remove the shaving cream.
5) Shave in whatever way you think feels best..but keep the return passes over the area to a minimum...more passes will dig deeper into the skin creating exposed areas that are not ready to be exposed on the never ending assembly line of replacement skin cells.
6) Rinse the shaving cream and hair off with a nylon loofah or scrunchie-type thing..don't dig at it, but use some pressure. This helps pull out any ingrown hairs.
7) Towel dry by patting, not rubbing.

Apply Witch Hazel to the entire shaved area. If you get some stinging more that a slight bit, you went too hard with the razor and need to lighten up on your technique.
You might get a rash the first few times, but if you follow these rules carefully, you'll stop them after a short while and the skin can be shaved without any discomfort at all.
If you insist on the use of a multiple bladed razor, try to get ones without the lubrication strips on them .This is that white or blue or green bar behind the blades that are supposed to give you a better shave...baloney! They just give you a false sense of security and you will shred your skin. I use the "Good News" dual blade ones..but more than two blades is just a gimmick.
Holding the razor handle too parallel to the skin will make you use more pressure than necessary..as the blades aren't making a good contact to the skin and you think you have to press harder to get a clean shave. Hold the handle more vertically to the skin. This is especially important on shins, ankle bones and toes if they heed it.
If when you are shaving you feel more hair showing up or popping up from the skin surface, you didn't get the skin clean enough or allow it to get wet enough. Human oils will resist the water and keep it from penetrating the hair and the skin itself will actually be dry under the immediate surface and won't push the hair to the surface so it can be cut off.
Shave as the last step in your showering process..but be careful of hair conditioners getting on the hair you want to remove. It will make it rubbery and it will not cut off cleanly.
Sometimes I use a cheap-o hair shampoo
without conditioner to strip the skin of natural oils before I lather and shave. Those shampoos are designed to remove human oils and they work quite well...just don't shave with them as they are the wrong product for that.
(PS: shampoos
without conditioners also remove human oils from things like collars and clothing that have that "ring-around-the-collar" problem. That ring is just human oils.)
I have a trick for shaving around the nipples if you have any strays there.
Just use the index finger on the hand not holding the razor to push down on the nipple...into the chest...and then shave around your finger. It protects the very sensitive nipple and raises the hairs to full height to make them easier to remove. Press the razor rather gently as you are now opening the skin up a lot and it can get razor burn!