Hey! I'm new here! and as a french speaker going to an english school, i'm gonna try to help clear things up!
In french, we don't pronounce the 
n's in Lanvin/Louboutin/Givenchy like in spanish or english...that is, we don't pronounce it at all! If you say 
-in- in spanish or english, you can still make out the 
nnnn-sound. If you pronounce it the french way, it makes a more nasal-y sound. So the pronunciation 
loo-boo-tin for Louboutin is good...if you read it the french way! 

 I cant find an equivalent for the french 
-in- in english though. The 
-an- and 
-en- are pronounced the same way in french, the way you would pronounce it in J
eanPG or Christi
an Lacroix/Dior.
Also, that reminds me: the 
G is soft in front of an 
e, 
i or 
y and hard when in front of an 
a, 
o or 
u. The hard sound is how you would pronounce it in english (game, give...but not gem!), but the soft sound is similar to the french 
J-sound. I say "french", because in english the 
J or soft 
G sound are more like 
djee...
Okay, I don't know if that made any sense, or helped anyone, but that's all i have to say for now!
