Wild camping is camping outside of campsites, such as often when wilderness backpacking, but also as an option e.g. when driving through sparsely populated areas, going down a river, sea kayaking or cruising on small craft too small to provide berths.

Basically, you should follow the following rules when wild camping:

Do not leave a garbage (dig in toilet paper)
Do not cause permanent damage to nature and landscape
Keep calm
Do not disturb the wildlife or feed wild animals
If possible, do not make a fire (in the dry summer months are often regional prohibitions for the firing of open fires pronounced!) Or dig a hole for the fire, which you should absolutely shuffle before moving on

Understand
Rules on wild camping vary from country to country. While in e.g. the Nordic countries, the right to access allows pitching up your tent nearly anywhere away from built up or cultivated areas, camping in many other countries is allowed only at campsites.

In national parks or similar, wild camping may be restricted to backcountry areas or disallowed altogether, with designated areas offered instead, often for a fee but with some infrastructure.

Depending on destination, wild camping can be too dangerous because of e.g. crime, wildlife or risk of severe weather.

As wild camping more or less by definition means camping without infrastructure, you should be prepared to take care yourself of needs such as cooking, water and toilets. Campfires are allowed in some countries but not in others, and may be problematic because of risk of wildfire.

Budget travellers sometimes sleep rough, i.e. wherever they find a spot, which can mean normal wild camping where possible, but also sleeping with little shelter in less convenient places.

Eat and drink
If camping along a road, you may be able to use restaurants for most meals and just eat light cold meals at your camp. Outdoor cooking is also an option, at least with a camping stove.

In some areas you may get part of your meal by foraging, such as picking berries for your porridge or desert – or even by fishing.

If you carry food or have food waste to take care of, mind rodents and bears, which could smell them.

You will need water. With a car, transporting water is not too difficult, and in some countries it is easy to replenish at fuel stations. In some areas there are enough sources of potable water in the wild. Often the water has to be purified, by boiling or by other means.

Water is needed also for washing your hands and your dishes.

If having water or other drinks in bottles, used bottles have to be taken care of.

Sleep
In most areas you want to have a tent or similar, at least a tarp suited as shelter. What kind of tent you need depends e.g. on weather and pests in the area.

Hiking mattresses are necessary for a comfortable night in many areas, in cold climates they may be important also for survival. In emergencies a thick layer of twigs can serve the same purpose. A hammock or tent bed can be useful to avoid snakes, scorpions and the like – in temperate climates few of these are active in the night, though.

Sleeping bags are easier than duvets or blankets to carry and use while camping. Note that night temperatures can be low also in many warm climates.

Choosing the right place to camp will often make the night much more comfortable, and sometimes safer. Considerations include:

Choose a site out of the way of possible criminals.
Choose a site out of the way of dangerous wildlife. The shore of a river where animals gather to drink, or the path to it, is hardly the best choice.
Do not camp where there is a risk for flash floods.
When you want to avoid possible hard winds, camp in the valleys and in or by forest. Lowlands and shores can be moist and cold in the morning, though.
A moist area with no wind will probably be where mosquitoes gather. Some wind is useful also if the nights are warmer than what you like.
You may want sun in the evening and the morning. In summer at high latitude, a sun rising half past three in the morning can make your tent a sauna while you still would like to continue sleeping. Some shade could be useful (also in hot climates if you are staying the day).
If there is water in the wild, usable for washing your hands and dishes and perhaps for refreshing yourself in the morning, you want to camp nearby.
Find a spot where you can put up your tent and sleep comfortably; you want a smooth dry surface.
If you want a campfire, that adds considerations of its own.

Cope
Without toilets, you can use advice for leave no trace camping.

In some areas you can take care of your hygiene by bathing in a lake or river. Avoid contaminating the water with shampoo and soap. You might want to do all the washing proper some distance from the water in consideration of those drinking the water downstream.

Stay safe
Depending on where you camp, risk of crime, dangerous animals or cold weather may need to be taken into consideration.