So I spent my entire first playthrough of this game being real nice to leiliana, y'know buying her nice shoes and pretending I cared when she talked about her mother and the Maker and I got to the point where I literally couldn't get her approval rating any higher but then the bitch turns to me just before we're all about to probably die and says "You are a true friend" and I'm like "Maker NO! I'm in THE FRIEND ZONE!"
 
God damn that's like a 45 hour playthrough and if I ever want to get the 10G achievement for getting in her pants then I am going to have to play it all again with her hanging around talking about shoes and how the Maker has a plan for all of us but screw that because it's boring; I'd much rather pretend I'm interested in hearing about Flemeth and how the Circle of Magi suck balls 'cos at least I KNOW Morrigan will put out by the end of the game.
 
Also being an arsehole to everyone is way more fun then trying to solve everyone's problems; Morrigan is soooo right

hahaha yea i barely got that achievement first playthru on my second i just social linked the shit outa everyone make sure u do the character specific quests they help alot and give them gifts they like for like +10-20 points leliana likes religous stuffs and flowers

I had the same problem you had except I didn't get as far as you did when I realized I was in the friend zone so I started over. Basically Leliana has two tracks to 100 approval, the friend track and the romantic track. In order to get on the romantic track you need to correctly answer one of two dialogue trees. The first one you can initiate as soon as you get her and the second one happens after you do her personal quest.
 
Also, why settle for one? If you're crafty you can have Leliana, Morrigan, and Zevran at the same time.

I didn't expect it to be possible to actually fail at the romance stuff; I remember with Mass Effect it was virtually impossible not to end up with the blue alien chick
 
What gifts does Morrigan like?
 
Or is it not important because of her offer at the end of the game anyway?

" So I spent my entire first playthrough of this game being real nice to leiliana, y'know buying her nice shoes and pretending I cared when she talked about her mother and the Maker and I got to the point where I literally couldn't get her approval rating any higher but then the bitch turns to me just before we're all about to probably die and says "You are a true friend" and I'm like "Maker NO! I'm in THE FRIEND ZONE!" God damn that's like a 45 hour playthrough and if I ever want to get the 10G achievement for getting in her pants then I am going to have to play it all again with her hanging around talking about shoes and how the Maker has a plan for all of us but screw that because it's boring; I'd much rather pretend I'm interested in hearing about Flemeth and how the Circle of Magi suck balls 'cos at least I KNOW Morrigan will put out by the end of the game.  Also being an arsehole to everyone is way more fun then trying to solve everyone's problems; Morrigan is soooo right "

How exactly do you trigger Leilana's quest? I have 100 approval with her and the only dialogue options I've had forever are for her to tell me stories. 
 
On the other hand, we kissed, and Wynne gave me this warning talk about getting involved.  
 
Am I really at the whims of fate, waiting for a random encounter from her past? 

" How exactly do you trigger Leilana's quest? I have 100 approval with her and the only dialogue options I've had forever are for her to tell me stories.  On the other hand, we kissed, and Wynne gave me this warning talk about getting involved.   Am I really at the whims of fate, waiting for a random encounter from her past?  "

" take this with a grain of salt, but i heard that if you get some characters to 100% approval ratings, they don't want to have romance scenes, or at least for morrigan. The key range is somewhere between 50 and 90. but this might be complete BS, i just saw it on the forums a while ago "