If going unconventional, security is often going to be an issue. Consider placing multiple GPS tracking devices in hidden spots with valuables. Video cameras and locks are also especially helpful when going unconventional. Don't forget about free showers at the YMCA if you sign up for their low-income program for a free membership, which is a great prospect if you have a low income & are going unconventional. Also, consider combining resources with one or a few other trusted people if going unconventional to split costs. The more socially adept you are, the better partner you will pick and the better your chances for developing a relationship which stays beneficial for both parties involved. A parasitic relationship, either way, is a recipe for failure where they will want to leave you or where you will want to leave them. 

Various Possibilities:

Find campsites & other similar unconventional low cost or free places to sleep here. Keep in mind that the list is not comprehensive, and it's best to also search Google Maps for campsites. Campsites sometimes merely allow tents, but at others times are set up to host RV's cabins, etc. 

House Sitting is a solid option and there are many different opportunities for it if you are open to having a roof over your head while also having some responsibilities for that home, such as feeding the dog while someone is away on vacation, etc. Here is a forum of various people's resources and experiences as well as questions with house sitting. H

Parking lots - Find Walmarts that let you park overnight here. I met someone near Vail, CO who lived at a Walmart for whole seasons in a van that they had converted to be more like an RV with a bed in it. He was one of my ice climbing guides. 

Liveaboarding - Some boats sell for practically nothing (check Craigslist - I see a boat with a trailer that ran last year with a cabin for $200 on Norfolk Craigslist at the time of this writing), sometimes even being given away for free (check Freecycle & Craigslist - I see a free boat w a free trailer on Craiglist in Norfolk at the time of this writing), and you can find places to live on a boat for free, especially in places near free dingy docks such as in downtown Hampton on the Hampton River. Be sure to check local laws if going that route. At other places, you can live on a boat for as low as a few hundred/month. At Ocean Yacht Marina in Portsmouth, for instance, you can have a 23' boat paying $195.50/month to live aboard it ($8.50/month/ft w annual rate) which includes water, with an additional fee for power at 11 cents/kilowatt, which is close to the rate you'd be paying at a house. Keep in mind solar options to avoid even the expense of power if you can afford panels and batteries. If going that route, go online and look up all the local marinas, and start with my list here. Also, there are places where you can anchor your boat for free, although in those cases, having video cameras, GPS trackers on valuables such as a dingy or kayak, & locks on your boat are important to deter thieves. Also, having a paddleboard and a car with a paddleboard rack are helpful if anchoring your boat. I have seen where someone anchored their boat for free with no cameras and it was vandalized over time. Some questions to ask for marinas include the following:

1. Are live-aboards allowed?

2. What is the cost for those staying annually (or whatever other time you want)?

3. Is there any additional cost for water/electric and are they included?

4. Are showers available?

5. Does the boat need to be approved before I can book the slip?

6. Is wifi available and at what cost or is it included?

7. Does the boat need to be insured?

8. Is parking available and is there any cost to that?

9. What is the lowest low tide the dock experiences?

10. Are there laundry facilities and is there a cost?

11. Are there minimum or maximum sizes for boats?

12. Are there any other requirements for liveaboards (some ask for references, might check your credit, do a background check, etc.)

You can own a lot at an RV lot, as you can see here. 

You can own property and sometimes have an RV on it, as you can see here. 

Train stations and police stations are also options sometimes, but it depends on the place. Some will let you and some will kick you out. 

AirBnB - at the time of this writing I'm seeing as low as $10/night in Hampton Roads

Jobs/Interships that include housing - If you can't find any jobs locally or nationally, and are open to working for food/housing or going international for higher paying jobs that include housing, click here. For the homeless that are willing to work and can get along well with others who are unable to find jobs or shelter, this one is an excellent prospect while seeking a more permanent occupation or for the long term. In some cases, you might only need to work 4 hrs a day, & sometimes even less, for housing and food. Just one of the resources I list on that document have 29 opportunities presently in VA at the time of this writing. Sometimes these options are limited to only 1 person or 2 people, but not always. Sometimes there are minimum stay requirements and other requirements, but options vary widely. 

Craigslist - at the time of this writing I'm seeing as low as $250/month including utilities and wifi for someone who is working, on social security, or disabled and on disability (basically any form of income that would adequately cover the rent and your additional expenses in their eyes). If something like that is not available when you look, keep checking back. If it's not available in Hampton Roads, you can always check other locations as well. In some cases, there is work that someone will request to subsidize the rent.