Seduction isn't only pick up alone, but also about improving yourself and the way you react in different situations. I feel like every man should see this post:

How to Deal With a Crying Girl:

1. Put your hand on her shoulder to start.

2. If she starts crying harder, put your arm around her shoulder.

3. If she keeps crying, pull her into a bear hug.

4.a. Once she stops crying, or if she pulls away, pretend nothing happened. Make stupid, completely unrelated jokes. Seriously, the stupider the joke, the better.

4.b. If she has a specific/valid (ie. not hormone induced) reason for crying, such as the death of a family member, say: "I don't know if it's worth anything, but I'm here for you." This will get you a bajillion bonus points.

This way, she can back off/get control of herself if she isn't comfortable crying to you (assuming she is at the point where she can control her tears). Never go for a half-hearted hug, on the receiving end that feels like you don't care and just want her to shut up. Even if you feel that way, showing it will just make it worse. You don't have to say anything. Unless you have personal experience with whatever is making her cry, anything you say will make you seem insensitive. If you feel confident, make quiet shushing sounds, like you would if you were rocking a baby.

Bonus Points: Carry a handkerchief and offer it to her when she is done.

Disclaimer: This won't work on girls who are crying because of you, because they are angry or because they are angry at you.

tl:dr- Voldemort hugs suck, bear hugs are awesome.

Source: http://www.reddit.com/r/AskReddit/comments/vozna/i_just_read_the_giving_tree_to_my_class_and/c56la48?context=1