D'en--how to you it and it is required?

Question

As you don't have a skill relating to d'en, I'm linking this to the skill related to de phrases and en.

I'm guessing that d'en, as I keep hearing it, replaces "des/de + noun" (though I'm still somewhat confused about it). But it is really necessary to use d'en? Couldn't you just use le/la/les (or in some cases, ça/cela). As in "J'aurais mieux fait d'en prendre." could I just say "J'aurais mieux fait les prendre"?? If d'en is required, how do I know when I need to use it as opposed to le/la/les (apart from 'fixed' expressions like "d'en haut")?

Cécile Janty-Davies · Accepted Answer

Hi Michelle,
 The 'd'en' is because of the expression -
'faire mieux de' which is always tricky to translate in English.
e.g.
Le jour où je l'ai rencontré , j'aurais mieux fait de me casser une jambe = The day I met him I'd have been better breaking a leg
Tu ferais mieux de le contacter aujourd'hui = You'd be better contacting him today
J'aurais mieux fait d'en prendre = I'd have been better taking some 
Vous auriez mieux fait de les emmener avec vous = You'd have been better taking them with you
The pronoun rules are the same as always.
Hoe this helps!