Times thrice.
After the event boss we did a daily heroic - which was Azjol Nerub - and found we were randomly getting Lovely Charms. It was only when the warrior thunderclapped the small adds just before the drop after Hadronox did I realise that: 1) Killing blows were required and 2) They had to be a non-grey level. So knowing this, the best places to farm would be instances where there were quick kill quick respawn mobs like the Stratholme zombies or areas where you control a vehicle or use bombs to mow down hordes of enemies like the bombing run quests in TBC. I opted to farm the Lovely Charms in Ulduar:
This technique may end up being hotfixed, but it's doubtful, due to the many ways of exploiting it. Some people do bombing run quests in Icecrown, or even running over the bone guards in the Battle Before the Citadel daily. But the fastest is just spamming fireballs in Ulduar. These Lovely Charms convert into Lovely Charm Bracelets, which are then traded for the Love Token currency. In order to complete the meta achievement, you will need:
My Love is Like a Red, Red Rose: Solo either Old Kingdom or Utgarde Keep normal until the San'layn.
Dangerous Love: Just complete the questline, gain 5 Love Tokens as well.
Nation of Adoration: 4 Lovely Charm Bracelets (Also gain 20 Love Tokens in the process)
Shafted!: 10 Silver Shafted Arrow: 10 Love Tokens
The Rocket's Pink Glare: 10 Love Rockets: 10 Love Tokens
Be Mine!: 1-3 Bag of Heart Candies: 2-6 Love Tokens
Sweet Tooth, Lonely?: 1-2 Box of Chocolates: 10-20 Love Tokens
Flirt With Disaster, Fistful of Love: 15 Handful of Rose Petals: 6 Love Tokens
I Pitied The Fool: 5 Love Fool: 50 Love Tokens
Lonely?: 1 Romantic Picnic Basket: 10 Love Tokens
Flirt With Disaster: 1 Perfume: 1 Love Token
In total, 113 Love Tokens. Considering Nation of Adoration and Dangerous Love, thats 92 extra Lovely Charm Bracelets that are needed to be converted to Love Tokens to complete everything. It's not hard, just time consuming! I did it all within a few hours:
