(I usally finish my burnout in 2nd... make sure to try to release the line lock or break under full power and burn away from the box... I then come to a complete stop and shift into N... this gives me a chance to clear the motor and then pull back into first. If you dont go into N and you get flustered one day you could stage while still in 2nd..)
If using a Torqueflite do not do 1st geara burnouts it will cause the sprag to fail resulting in the drum exploding and removing your foot.
I start in 2nd hit it very hard right up to about 5500 then shift to 3rd and as it starts grabbing let it roll out and ease off the throttle. Clean out the engine in Neutral drop into 1st and roll up to stage.