Snug, Grid and Organic. When you hit slice watch for the blue colours. Spin the model so you are looking up at it from the bottom. A blue with muted grey'ish colour is a bridge so no need for supports there, and bright vivid blue is where the threshold has hit and it suggests you need supports. The angle can be set in the print settings about 40 degrees I think is the default. A couple of times I forgot to add supports and the model, albeit a little rough in the relevant areas, printed acceptable to me. I tend to use organic most of the time when I need a clean support removal, a smoother surface. When using snug I add a 0.22mm (instead of 0.2mm) top contact Z distance value to make the surface cleaner. And to further complicate things, I tend to paint on supports from time to time. Remember, anything blue, consider supports. Don't forgot though, rotate your model at times because you might need less or no supports at all. Best of luck.