Blend everything but not all too long (for about 20-40 seconds). It should appear milky. Over blending can turn it slimier.
Keep a bowl with a cheesecloth ready.
Pour milk through the cheesecloth so that the good stuff is collected in the bowl. Don't press the milk as this will release the slime. Just let it drip into the bowl.
Use the strained milk as is or flavor to your liking. *see Notes
Try to use cooled oats as this will decrease the chances of slime forming. Rolled oats are your best choice. Instant oats can get a bit slimy too but are another option. In the video I used instant oats and it turned out fine and not slimy.
Use cold water. It reduces the chances of slime forming.
You can choose to flavor your milk with syrups, stevia, sugar, extracts or powders such as cocoa powder. Add a small quantity, taste and adjust to your needs. More detailed flavor options in the post.
Just FYI this is not a Barista Oatly commercial style oat milk. Look up "Advanced Options" in the post for more info about that.