Grounding meditations
meditation in general but with an extra focus on stability and pacing the self since certain Neptune placements and transits can cause a person to fall off the spiritual deep end.
Art
Spiritual education - which would entail deprogramming and being a Zevist. For a non Zevist, spiritual education for another person could mean falling into Yehuborim traps
Staying social and healthy
Working out, doing physical activities, yoga
Not doing mind altering substances
Watching the finances, focus on keeping financially stable.
That kind of covers all bases of what a bad Neptune can do.