You may need to avoid restricted or controlled airspace in the task area. Having a current chart available will be very useful when planning the task. If you're using electronic flight planning software you will need to be sure you have the current airspace information and that it is complete.
Remember that you may not be going direct along the task, so make a note of any airspace that might be near the task route to reduce the chance of chasing lift off course and clipping nearby airspace.
For badge tasks, if you are going to enter controlled airspace, including entering a GAA, it is best to make a note for your OO so there is no question that your flight was in compliance with the regulations.
For contest tasks, you generally don't allow contestants to get individual clearances because there is the possibility that some contestants will get clearances and others may be unable to get clearances. Having twenty or thirty gliders changing to the control frequency, requesting clearances, changing their squawk code, acknowleging their clearance, calling up as they leave, changing back to the contest frequency, is not practical.