I am a 4a (with some random 3C and 4B sections), high density, medium strands and a cottony, webby texture.
I finger-detangle almost exclusively and I only finger detangle after shampooing with globs of rinse-out conditioner in my hair. My hair is always in 4 sections when I wash and once the rinse-out is in each section of my hair, I then split each section into 4-6 subsections and proceed to thoroughly finger detangle.
I have detangled before washing, after deep-conditioning, while deep-conditioning and now after washing and before deep-conditioning. Before washing made me too tired to actually finish wash day, after deep conditioning made me dread washing out my dc and the detangling after, during deep conditioning used too much deep-conditioner (DCs are not cheap!). I have reached a happy medium. Since I wash and condition in the shower, once I'm in the shower, I can go ahead and get detangling out of the way. Also, my hair detangles easier when it is wet and using rinse-out conditioners before DC-ing gives my hair a nice base of moisture so I don't have to use so much DC. My hair is so long and tangles so easily that getting detangling out of the way as soon as possible but in a way that makes detangling as easy as possible makes me not DREAD wash day as much.