I found the following helpful after nebulizing and aerobika:
1. Breathing control
Breathing control helps relax the airways. You should
breathe in through your nose and out through your
mouth with very little effort. Use normal, gentle
breathing with the lower chest while relaxing the
upper chest and shoulders.
A good way to do this is to place one hand on your
stomach as you breathe. Remember to breathe gently
so you relax the airways. By using the pursed lip
technique when breathing out (pursing your lips like
you are kissing someone), you create back pressure in
the airways that stents the airway open longer. Repeat
breathing control for six breaths before moving to
chest expansion exercises.
2. Chest expansion exercises
Breathe in deeply. (Some people use a three-second
breath hold to get more air into smaller airways and
behind the mucus.) Then breathe out without forcing
the air out. This may be done with chest clapping or
vibrating, followed by another cycle of breathing
control.
3. Huffing or huff coughing
Also called forced expiration technique, huff cough at…(I lost the rest sorry)

Airway clearance consists of using an airway clearance device like an Aerobika, or performing huff coughing or using a percussion vest while or after nebulizing. I do it every day, whether congested or not. You might be surprised how much mucus is loosened by the saline and will come out after the nebs.
Sue