When baking a cake, the recipe always calls for sifted flour and most people question why. Back in olden days, people sifted flour to remove impurities like insects and husks so this step was necessary. These days, devoted bakers still sieve flour in order to (1) Aerate it, making the batter lighter and (2) Remove any flour clumps, so the flour is evenly distributed throughout the cake.
Most chefs use the sieve below as it's versatile and can be used for other prep work. But, I find the vintage flour sieve with manual crank to be the best option. It comes with a grip action crank or rotating action crank.
At home I use a flour sifting pan, it's like a chef's sieve but bigger. To sieve the flour, you have to hit the sides like you're playing the tambourine.