Combine white sugar, light brown sugar, cinnamon and salt in a small bowl.
Place unsalted butter in a small heatproof bowl and microwave until melted, about 30 seconds.
Remove puff pastry and cut in half. *The key to handling puff pastry successfully is keeping it cold. Place one half in the fridge while you work on the other. See more tips above.
Gently roll out puff pastry to make it slightly thinner and larger. Prick holes into the puff pastry using a fork (this ensures steam can escape the puff pastry so it doesn't puff up like crazy).- If making a tree or twists, roll it into a rectangle.- If making a star, roll it out into a square and then cut it into a circle by using a circular object and tracing it (see video above).
Brush about half of butter onto puff pastry generously, followed by a generous dusting of the sugar mixture. Place in fridge.
Repeat with other half of the puff pastry. Then place this half of puff pastry on top of the first half.
Cut into whatever shape you'd like (see above for step by step videos!). Brush one last bit of butter on top and one final sprinkling of sugar.
Bake until golden brown, about 18 minutes. Let cool just slightly before serving.