short questions thread next time.
Class items are rarer than general items and higher quality items tend to be rarer than lower items (ancient armor vs quilted armor),
but that's all RNG and you can't rely on that.
Sewers are probably bad to farm sacred items. Try duncraig which has a sacred bias.
What I do to make it easier is set up d2clicker to notify me about items I want, so I don't have to focus so much on what drops, because it just pings whenever it sees a specified item.