I try to use my neti pot often (though not as often as I should!) and it seems like every time I use it I have to find that sweet spot where the water comes out my nostril and not down my throat. I usually start but tilting my head to the side and then I find I either have to tilt my head forward or back.
My husband and uncle both have deviated septums, and with one nostril it seems they never get the water to flow through no matter how clear their nasal passages may be.