Hygiene is important for physical and mental health. Therefore it deserves a pretty thorough breakdown of your options.

Bushing your Teeth:

This is pretty easy, you can do it basically anywhere. Typically I brush my teeth during my last bathroom break before I settle down in a parking spot. If you forget though, just brush you're teeth on the side of the road. No harm done. Flossing is made SO much nicer if you buy some flossing picks.

Showering:

Showering is the tough one and usually the one people have issues with. First let's talk about showering options because there are two: full shower and sponge bath. A sponge bath is simply a wipe down with a wet towel. The nice thing about this, is that you can do it at really any bathroom. The negative is that it simply doesn't clean you off that much and you can't clean everywhere. That being said, it is MUCH better than not washing at all for several days.

The full shower is where the money's at, and there are more options than you would think.

Shower Option #1: The Truck Stop

Truck stops have showers for truckers, I mean how else do that live out of their trucks and stay pretty clean? This option is great if you are aren't staying in one place for a while They usually cost a couple of dollars and can range from gut wrenchingly gross to pretty fancy! Just make sure you have flip flops.

Shower Option #2: Gym Membership

You can pick up a 24 Hour Fitness membership and take care of all of your personal needs. These range from long term plans for as low as $40 to month to month $70 memberships (depending on what gym and where). This option is great if you are staying somewhere for a while, and arguably a must. The other benefit of this option, is you can just park and sleep in their parking lot :)

On the other hand, if you are just passing by, you can ask for a guest pass to a gym. sometimes they will leave you alone to stroll the halls to check it out. This can obviously only be done once, but for short trips it can do the trick.

Shower Option #3: Pool Hall

This can get costly, but its still an option. Swimming pools have locker rooms with showers that you can use.

Shower Option #4: The Beach

If you are somewhere around the coast, then you can usually find an outdoor shower. These are typically set up on popular beaches so people can rinse off after a swim. You don't have to feel weird taking your shampoo and going full ham on your body wash because a decent number of people do this. It is a little uncomfortable, though, I will admit. It just takes a while to get used to "showering" in such a public place.

Shower Option #5: Religious Building or Organizations

Depending on what religion and what type of building you find, you can sometimes shower at religious meeting halls. Generally speaking, religious organizations are willing to help people out. If you are respectful, nice and open with them, they might be towards to as well.

Shower Option #6: Public City Buildings

In some cases, public city buildings have a showers in their bathrooms. For example, I have been in lightrail service stations that are open to the public and have a shower in the public restroom there. You just have to be aware of the hours of operation.

Washing Your Clothes/Sheets

Easy: Laundromats