Not sifting dry ingredients
You’ve probably heard that you don’t need to sift your dry ingredients anymore. After all, whisking is the new sifting, right? That’s not entirely true. Sifting your flour will help break down any clumps of the powder, which could lead to pockets of pure, disgusting flour in the finished pastry. This is definitely not something you want to serve your dinner guests.
If you don’t have five minutes to whisk the flour, just pour it all into a sieve and sift it instead. This will also help aerate the flour, which will help provide some lift in the pastry or bread as it cooks.