In addition to the above suggestions, sleeping on an incline may help at night, continuing proper oral care, as Cheryl mentioned, and some find help with thick mucus using robotussm or mucinex, rinsing with papaya or pineapple juice, tea, water diluted meat tenderizer to rinse, drinking water often, other carbonated drinks. Some have used a facial steam apparatus, but I never used it. There are oral sponge sticks, forget name, usually green or yellow, pre-moistened, that can get in the back crevices as well.

Good luck.