Makeup and body brushing??

If you handle a faceup properly, and there was no mistake done by the artist (like sealing in wrong weather conditions) or no materials acting up, a faceup can technically last for many many years without issue.
However, if you regularly touch it with oily hands, scratch it with your nails, let it drop on hard surfaces etc. it of course ages badly.

Usually people only change faceups for two reasons: it got damaged, or they want a different look for this doll. Especially when you have to ship them out to get them painted it's just too expensive and annoying to get them repainted every couple months

People usually do not go for body blushing for two reasons: it ages badly, and unless your doll is always naked you never see it anyway.
Body blushing scratches fast just by handling the doll. Sealant stains quickly from dirt on your hands or dye in clothes. Easily handling the body is not possible once it's all blushed. And once it starts scratching and chipping it looks pretty ugly on the doll.
It's usually best to do a minimal blushing of areas that are actually visible (like the collar bone).

 

It depends on what materials the artist uses, and the doll's environment. They could last decades and decades! You can change it every day if you wanted... but I believe most that do faceups themselves will re-do one when they are bored with what they have done, the sealant chips or the sealant starts to yellow. Everyone will have a different method to decide for themselves. The body blushing makes the doll look more realistic. Shipping is expensive if you send your entire doll out for this service. Also, the movement of the joints and changing clothes can chip the sealant or the dyes can transfer onto the doll. This isn't usually a big deal for resin, a magic eraser tends to clean that easily. It made cause pigments to fade if the doll has those on the body. I personally like the bodies to be blushed, but I've only completed this for one doll myself. It's much, much easier than a faceup, IMHO. It does take much more time and sealant though. I'm sure others will have different experiences than me. Everyone weighs out the pros and cons, and everyone will value these points differently. I hope that my answer helps!

 

Can't speak to professional face ups but I think it firstly depends on quality of materials and methodology by the artist and secondly on how one handles said face up.

The reason I don't have body blushing was because it wasn't offered as an option. I'm still too scared to give it a shot myself for now but maybe in the future.

 

Some of my second hand dolls came with body blushing. And it is lovely. But since I like to see for my dolls, the blushing only appears when they are on my worktable...and may be damaged as I work on their clothes.
I have one new doll who came blushed...because I thought "body brushing" on the order form meant sanding. >\\\< It is gorgeous but mostly hidden by his clothes. ;}
As to how long faceups last, as folks say it depends how you treat a doll. Keeping them away from sunny windows & being careful how you handle them. One of my CPDelfs, from 2005, still has her factory faceup & it looks perfect. A few faceups have yellowed due to the fixative aging poorly. One faceup I had redone in hopes of getting a less pouty look for the doll. And another had to be sent back to the artist because I didn't pay enough attention when putting goggles on her & scratched her eyebrow paint!!
A couple of times I've decided to update a dolls look with a new faceup. And each time there was an unexpected adjustment time afterwards, getting used to their new, different look & mourning the loss of the old before I fell madly in love with the new.

 

Faceup longevity tends to vary - I've had to have my oldest doll repainted some years ago because his faceup colours faded drastically. My second oldest doll is still fine after 15 years.

Body blushing is a personal choice and a lot would depend on how much you play with/pose/redress your doll... I personally don't think it's worth the time, effort and cost because it always wears off around the joints and anywhere its touched by things like jewellery, clothes fastenings (hooks and eyes, press studs etc.) so it quickly starts to look awful

Here's an example from my Chobi Unoas whose body blushing started to deteriorate almost immediately:



Also, most of my dolls tend to be dressed most of the time so body-blushing anywhere other than hands/wrists, shins/calves, and neck, is wasted most of the time anyway.

Teddy

 

I tend to change my dolls' faceups every year or two, sometimes more often. I do all of my own faceups, so it's easy for me to wipe and redo any time I like. I usually do it either when one becomes damaged or when I feel like my skills have improved and I can make the doll look better.

Full body blushing can get stained easily and chip easily, it's just the nature of it. I get around this by only doing partial blushing--I usually only blush hands, feet and chest. I don't blush around joints or any part that isn't going to be visible in photos, like the hip piece. Most staining clothes I've noticed has been from pants, so if I don't blush the hip piece or legs, it's a lot easier to remove.

 

Having read up on DoA about the trials of body blushing, I was convinced I wouldn't try it, but after getting my doll, I'm really tempted to due to all the sculpted details... it seems a shame not to bring them out with some color!

But I think I'll stick with face/hands only. I'm too afraid of chipping and staining.