This guide explains the drift launch in detail.
It starts with a simple drift launch and then shows another version that uses wrapped up lines (for locations where you are more likely to become tangled, such as water with seaweed near shore).
Creating a tangle (that could loop your kite) is a real possibility during a drift launch. Therefore, this video focuses on managing your lines and avoiding tangles. It also looks at some safety steps to reduce your risks. Even then, bare in mind that a drift launch is not suitable for beginners, as you will not yet have the safety reflexes or kite awareness required.
It is safest to practice your drift launch in very light wind. In light wind, things go wrong more slowly and you have a bit more time to assess, untangle and use safety systems.