Two very useful tricks:

defaults write com.apple.dock workspaces-edge-delay -float 0.5; killall Dock

(to change the delay, in seconds, between hitting the edge of the screen with a dragged window and moving into the neighboring Screens desktop)

``defaults write com.apple.dock workspaces-wrap-arrows -boolean NO; killall Dock

(toggles whether moving to the next Space wraps around when you get to the last Space; i.e., keep going left and you’ll wind up in the rightmost Space)Â