A key technical gesture to properly and easily use a pastry bag.
Whipping Cream
Open the bag, folding the edges over your hand.
Use your other hand to open the bag fully.
Place the nozzle in the bag.
Cut off the tip of the bag with scissors.
Avoid cutting too much so the nozzle is held firmly.
Pull the nozzle to the open tip of the bag.
No more than 1/3 of the nozzle should come through the bag.