En la moda, de moda, a la moda

[poli]

Are they all good to use?

[ROBINDESBOIS]

THEY ARE USED DIFFERENTLY
Los pantalones campana están de moda. ( They are fashionable)
En la moda is used to talk about opinions En el mundo de la moda hay mucho intruso ( Fashion as an industry)
A la moda is used in ir a la moda, A mi hijo le gusta ir a la moda My son likes wearing fashionable clothes or is fashion-conscious.