Remember that the secret is to relax your lips so that they flap up and down freely. Never press the mouthpiece tightly against your lips as this interferes with the buzzing. If you really press too hard, you'll end up cutting off the circulation to your lips. Time and again you'll catch yourself pressing the didj too hard against your lips when you are trying to master something new. Remember that all you need to do is make a seal.
Beginners often overblow.
Once you have blasted out your first drone, relax and reduce your blowing. You'll be surprised to find that you can still keep a nice drone going with much less air.