If positioning of right-angle fittings for your air/oil separator is critical, you can often substitute Teflon sealing tape with non-curing liquid pipe sealant. Slight rotation from full-tight may provide just the right angle for hose positioning.
Crankcase vapor oil droblets are more likely to be trapped when filter media is not super heated by engine heat. If possible, mount your catch can as far away from your engine (and lower than the valve covers).
Many people consider using thread locking compounds to prevent loosening of threaded hardware due to vehicle and engine vibration. Use Loctite 222 (pink) or equivalent for screws M5/10-32 or smaller and Loctite 242 (blue) for screws M6/1/4-20 and larger. If the screw contacts a non-metallic surface, use Loctite 425 (light blue)