Subohm is not as big of a worry as a short, and shorts are easy to come by when you first start wrapping and attaching coils.
The three most important things are the batteries amp load capacity, building your coils ohms above the amp load capacity of your batteries (using ohm's law), and always check the atomizers resistance after putting it together to verify no shorts exist.
The three most important things are the batteries amp load capacity, building your coils ohms above the amp load capacity of your batteries (using ohm's law), and always check the atomizers resistance after putting it together to verify no shorts exist.