Everybody always talks about the weapons they would bring, but what about soap, toothpaste, toothbrushes, cleaning water, and deodorant? They are all important for survival. If you don't use these, your teeth and body will smell terrible and rot about as fast as the average zombie.

Clothes
Also, you will need necessary clothes, bringing into account the season and where you live. If you are in any desert, don't wear heavy clothing. You will develop heat stroke. If you live in a tundra or on a mountain, wear heavy clothes so you don't freeze to death.

Washing your normal clothing may not be necessary, but washing any clothing that gets sweated on is necessary; your undies, socks, or they will rot away! Washing yourself will make you smell better, but as long as your pores remain unblocked you will not have severe health consequences from being unwashed (discounting parasites and infection).

Keeping Clean
If you don't clean yourself, why would anyone want to be near you? Regardless of location, there will be time to bathe (unless you are always running from zombies). Brush your teeth in the morning. Make sure not to use too much water. (If you want to save water use the soaps and shampoos that don't need water)

But take also sure you got some kind of neutral scent on you, smelling too good could probably attract more zombies and smelling too bad would drive away any survivor and potentially team-mate.

Keeping Your Weapon Clean
If you don't clean your weapon, it won't work, and that WILL land you in the most dangerous situation of all, being unarmed. Even the best AK-47 will eventually get dirty, and AK's are the weapons that require the least maintenance.

Basic Things for Keeping Clean (and Substitutes)

1. Hand Sanitizer/ Soap and Water
2. Toilet Paper/ Washable Rag
3. Toothbrush
4. Toothpaste
5. Baby Wipes/ Wet Naps/ Wet Napkins
6. Shampoo
7. Comb
8. Razor
9. Shaving Cream
10. Weather Appropriate Clothing