The use of automatic sketch relations can save us a huge amount of time in the sketching process. However we don't always want to create relations, perhaps you are working in a particularly congested area, so how do we turn these off?
The answer is not immediately apparent as there is no setting or command for this operation. When in a sketch simply hold "Ctrl" to turn off automatic sketch relations. Note this action only works for the sketch point you are about to click on and you will need to hold "Ctrl" every time you wish to create a new sketch entity without any automatic relations.
In the two pictures I am drawing two identical lines. In the first you can see I get cursor feedback trying to create horizontal and coincident relations. In the seconds image I get no such prompts.
By Jon Weston-Stanley
View the Video here