This needs to be said: Some of you guys should pay more attention to your hygiene.
There. I said it.
I'm not saying that I belong on the front cover of GQ or that I lead the local chapter of Metrosexuals. I'm just saying that if I can smell you from more than 12" away and that smell isn't a nice one... that's a problem. I have often played games at Games Workshop stores where I can get a whiff of someone who is standing by the table as I roll dice and deploy Guardians. And that's just not right. I don't get that while I'm waiting for my decaf venti triple soy latte at Starbuck's or as the cashier at the local IGA is scanning through my tofu and organically grown baby carrots. This is something I get rather often while dealing with Warhammer players. When I say "often", I don't mean every day; maybe one in 20 players are like this but... it's too much. I, therefore, have penned this for you.
Brushing Your Teeth
It takes a lot to get to the point where you are actually brushing your teeth too much, so don't be shy. Do it first thing in the morning, before bed, and after every meal. If you are running your tongue over your teeth and you feel food or plaque, go ahead and give them another brushing. Your selection of toothpaste is relatively unimportant, as the scent gets washed away by your saliva rather quickly and it doesn't do a lot for your overal dental health anyhow (did you know one of the chief ingredients in toothpaste is sugar?), but pick one you like and use it. A useful brushing should take a full 3 - 5 minutes, so don't rush through it.
One of the most overlooked aspects of dental health is flossing. I can't stress enough how important this is. Most halitosis (this is where you come in) is caused by food getting caught between your teeth and rotting, especially meat. You really need to floss at least once a day to keep this under control. Don't be put off if your gums bleed a bit at first because repeat flossings will cure basic gum disease such as gingivitis (which causes the bleeding). Trust me on this: Just keep flossing and you'll be ok. If you're really worried, see the dentist. But he'll just tell you to keep flossing (and that's his way of saying your breath smells like garbage night in Chinatown). The flossing is really important. While I'm rolling to make armor saves I don't want to smell the chicken sandwich you ate over the weekend decomposing between your molars. I can't read the dice when my eyeballs are watering.
Also, drink a lot of water. Dehydration is actually chronic among people in this culture, and the "pasties" contribute amply to bad breath.
This is a somewhat affluent society we live in. Everyone should be able to afford and maintain clean clothing, especially if you can fork over several hundred dollars for a resin tank made in the UK and delivered by courier. The first rule of thumb about clothing is that there is no reason you should have to wear the foundation garment (i.e. socks, underwear, undershirt, etc) for two days in a row or more. It's not unhygienic in the way that athlete's foot or gangrene are, but the effect is cumulative and if you're already having trouble keeping your body odor in check, you are not doing anyone any favors. Outerwear such as jeans, shirts, sweaters, etc. can sometimes take two days in a row (particularly items like sweaters which *should* have a layer of clean clothing between them and your body, such as would be provided by a T shirt). There is no reason, however, to push this rule and - in fact - lots of reasons to err on the side of caution. You should feel no shame about tossing any item of clothing into the laundry hamper, even if you can't actually smell anything on it yet. I'm not advocating the environmentally-unfriendly practice of doing uneccessary laundry, but I am saying that it's hard to trust your nose when it comes to determining if something is too saturated with "you" to wear again. Other people will smell your odor before you do. It's just a fact.
One little-known fact is that baseball caps can go in the wash. Some caps which use cardboard to stiffen the brim might pose some problem, but in general even those can withstand a good washing. Your hair secretes oils and collects dirt (especially if you don't wash it often, which we'll get to later), and your hat obviously will collect those. Dark, warm, humid places are the preferred breeding ground of bacteria, so do the right thing and remember to occasionally take the hat off for a few hours every day, and make sure you wash it semi-regularly.
Most people can figure out how much detergent to use when washing articles of clothing, so we won't cover that here. I will say, however, that most clothes (even darks) can take a very small amount of bleach while being washed, and the anti-bacterial effect is well worth the effort. Remember: Once your clothes come out of the washer and dryer, they should no longer smell. If you aren't achieving this, bleach may have a role to play in solving the problem.
There's little to say in this category, as most of the reasons behind bathing are pretty self-evident. You should take a shower or a bath every single day. You can do this in the evening or in the morning, but try to be somewhat faithful in this regard. I think the methods and process of it are self-explanatory, but I can offer some tips:
Use anti-bacterial soap, especially in the areas where the sun doesn't shine. Bacteria is your main cause of odor and cleaning it out of those warm, dark, humid areas we discussed earlier is a good idea.
Wash between your toes. Foot odor is usually due to bacteria gathering there, and so make sure you prevent that. Also important is drying that area because water that's left between your toes can be as prolific a cause of odor as not washing them at all.
Make sure you apply anti-perspirant as soon as you're done (before bacteria in your armpits has had a chance to collect).
When styling your hair, don't go overboard on the gel. The possibility of extra hold may be seductive, but the presence of gel and other products in your hair increases the amount of airborn shmutz that your hair collects and can also effectively "seal in" the scalp's perspiration and natural oils, thus causing problems that range from foul odor to acne. Do your best, as well, to wash whatever hair products you use out of your hair before your day is through. We don't always do this in our busy lives, but it's a good habit to get into. If you've had gel/styling products in your hair for more than 36 hours, however, get your melon under a tap immediately and wash it out.
You don't have to use shampoo every single time you wash your hair, but if you use hair products or you have naturally oily hair, it's not a bad idea. Some people feel it's better for their hair to alternate days when they use shampoo and days when they don't. If you're doing all the other necessary things for good hygiene then there's no harm in this: The important thing is that the water does its job, so while you can set your own schedule for shampooing, don't scrimp on the washing.
If you wear a coat, especially in the winter, know when to take it off. If you're indoors and you let yourself sweat for an hour before removing it, you're only making your problems worse.
Try, whenever possible, to buy quality footwear. Shoe manufacturers that use a lot of cheap or synthentic materials are likely to sell products that increase foot odor.
What you eat makes a difference in how you smell as well. A lot of processed foods will change the amount of oil your body secretes and, as we all know, garlic, onions and other strong foods will change the way those oils smell. Be aware, also, that while people commonly associate frequent farting with fresh vegetables, it's typically meat and fast food that makes the farts smell bad. If you really want to go the whole nine yards, consider a vegetarian diet.
While this is a less serious problem than, say, laundry and washing your ball cap, be aware that your beard/goatee can hold bad-smelling oils the same way your hair can and will often smell even worse because tiny food particles commonly get trapped in that area. Wash your goatee/beard semi-regularly.
Remember that hygiene is a cumulative effort; no one thing is going to solve your odor problems, but if you follow a regular schedule of bathing, laundry, brushing/flossing, etc. then the assorted facets of keeping yourself clean will lead to a much more presentable, pleasant scent and appearance.