Equipment to produce shelter is perhaps the third most important item in your bug-out bag, after the ability to purify water and to make fire.
Whether you find yourself in an off-the-grid situation, or are just preparing to camp out in the woods for some fun, having shelter is critically important.
There are multiple ways to make shelter, but the most common methods include popping up a small tent with poles, setting up a tarp with some rope, constructing a lean-to with the resources around you, or preparing a hammock.
Any of these options should serve you well enough, as long as each is properly set up, and different preppers and survivalists will have different opinions. You also need the ability to set up a durable shelter fast, in case darkness is fast approaching or bad weather is looming.
If possible, you should include in your bug-out bag more than one way to make a shelter, just as you should include more than one way to purify water and start a fire.