Usually I get very minimal DOMS, but if I have a week or more off from training I get terrible soreness, particularly in my glutes and thighs that leaves me hobbling around like I have arthritis or something. These are some things I've tried but I was just seeing if anyone else had any helpful suggestions or knew whether or not these things are effective.

* = I feel these have helped

For prevention:
magnesium (as amino acid chelate) (taken regularly) *
beta-alanine
bicarb soda
staying hydrated *

For treatment:
plenty of protein *
BCAAs
hydration *
arnica cream *
hot shower/bath *
walking
stretching * (although painful )
heat producing ointment (like tiger balm/zen liniment/wood lock etc.) *

Antioxidants. Blueberry smoothies. That's the only thing I've personally really noticed making a difference. Really haven't noticed anything from protein or stretching despite trying that many times. Couldn't say about the others. Being hydrated makes sense although I hadn't noticed whether or not it actually made a differnece...

For prevention, working into exercise gradually is one. And/or not taking too many days off inbetween sessions.

Unfortunately some people simply suffer DOMS & there is no 'cure', you could also lightly work the area the day after training, so say you do some squats for example & the glutes are sore, doing some bodyweight squats (or even assisted bodyweight by holding door frame, rack or similar to use some arm power to help lift & lower yourself), or some other full range of motion movement that lightly works the region.
Part of DOMS is certainly inflammation, so anti-inflammatories might be worth looking at (stuff like EFAs {both ALA & DHA}, ginger, etc).
Eccentric motion also seems to increase DOMS, so lessening the load, or time under load during the eccentric portion of a move might help
There may also be some benefit from microcurrent therapy? http://www.ncbi.nlm.nih.gov/pubmed/20538225

As far as I know the BCAA/leucine there is conflicting evidence about effectiveness for DOMS (although they quite possibly effect muscle damage post-exercise this doesn't always seem to reflect in the amount of DOMS you suffer from)
A massage will possibly help you (if you afford them regularly), stretching can help, but again the research is sketchy about that.
I even dug up study that showed perceived pain of DOMS was reduced by acupuncture http://www.ncbi.nlm.nih.gov/pubmed/18990049, but I don't think that's been looked into enough to seriously consider at this time.

Maybe the idea of a 'start-up' week would be a good idea where you go extra light, minimise the eccentric motion & work more slowly into the higher intensity stuff?

DOMS can really make you suffer. I've been unable to walk up or down stairs without gripping the hand rail for dear life & coming down like I'm suffering from some terrible health condition with DOMS in the past (experiments with 20+ rep squatting -that was DOMS!!!).

If anyone had a definitive answer to DOMS I think they'd be pretty rich by now!

The funny thing is, my partner is an TCM practitioner (and does acupuncture) and has a TENS machine, but I was too wussy to let him near the area. From my experience with the TENS machine, I think it would be reasonably effective for DOMS. I remember when I first got in weight lifting, I used to take Tienchi Ginseng for DOMS and it actually helped, I had forgotten about it. Also I've been thinking about buying a mixed antioxidant tablet, if blueberry antioxidants work. Also, I don't normally have more than 3 days off at a time maximum, but I hadn't been doing much since its been my exam period.

I used to get terrible doms after my workouts consisting of heavy squats and deadlifts but found what worked for me was doing a slow 1- 2 mile run later the same day.
I didnt stop the doms, but made them MUCH less severe

Maybe for a heavier guy (like a top end powerlifter) a decent paced walk would help them as well...just thinking out loud. Just thought a guy that big couldn't really run too far, but a decent paced walk might do a similar job for them???
It really makes sense as it has been shown active recovery can really benefit healing, so a small jog would be a decent option - I'd never really thought of that one before, I'll have to try it on a few people & see how they do (assuming I can convince them to jog after a heavy squat/deadlift session )

Speaking as the senior in these proceedings, it appears that blowing out birthday candles seems to alleviate DOMS.
Perhaps it is that "burn" is a thing of the past. I usually run out of gas before I reach exhaustion, and DOMS doesn't often catch up with me.
Remember Frank Zane's observation that the better shape you're in the less time it takes for DOMS to catch up. He noticed that when he was in top condition DOMS usually caught him the next day.
I'm working out pretty regularly and not getting hit with DOMS more that once or twice a week. I work out pretty early, about six or seven in the morning*, and have to remind myself to take a day or two off during the week.

(Note: I'm still a long way from my goals. But still having fun.

*Keep an FM radio in the gym and listen to the early morning news while lifting.)