This is my preferred way to add drip 1/2" supply lines. I have found that this method reduces the likelihood of damage from people walking in the area.
If you are using the install calculator, these are the parts that will be recommended. The 1/2" funny elbow is for connecting to swing pipe. This reduces the likelihood of damage when stepped on.
In this image the 1/2" tubing is black, but it is the same as the brown tubing in the other images.
Thread the coupling to the funny elbow and barbed adapter. It is a good idea to use Teflon for these fittings.
Press on the 1/2" tubing. This can be of any length, from a few inches to 100 feet or more. Personally, I try to keep them shorter than 30 feet to keep them at a manageable length. Just remember that this tubing can only supply around 4 gallons per minute ( 240 gallons per hour ). If you exceed 4 GPM, you will have poor performance.
Cut the line to insert the barbed ball valve. Simply press them back together.
Using barbed ball valves are not necessary, but it is my method of choice. This ball valve allows the water to be shut off to this section when it is not being used.
This is simply an example, it is highly unlikely that the tubing will be this short, it will generally run the full length of a garden or flower bed.
These are simply examples of how this supply line might be used.