As our line-up of expert mentors have already revealed, it's easy to walk into SXSW and walk out with a stack of business cards. The real difficulty begins when the party is over. How do you establish contact with everyone you've met? How do you keep those connections healthy and alive without looking desperate or crazy? These tech and marketing guru share their two cents. They've made all of their mistakes so you don't have to!

Follow up and follow through

1. Stay organized. Michael Robin, the marketing director at Rocksauce Studios, has a SXSW networking horror story. After mixing up her business cards with a colleague's stack, she found herself in touch with people she had never actually met. She explained her predicament over email, but the damage was done. "I never heard back from that individual again because it sounded like I was trying to extrapolate a story," she says. To avoid future embarrassment, she now writes her name on every business card she collects.

2. Forgetfulness is failure. In the SXSW rush, it's easy to let important connections wither on the vine. Rod Paddock, president and chief technology officer of Dash Point Software Inc., recognizes all too well. "It's easy to collect cards and contact information," he says, reminiscing about the potentially huge connections he threw away. "There are contacts that I wish I had kept going. There have been opportunities and I haven't followed up." Not trying is the only surefire way to fail.

3. Context is key. "I try to take some sort of a note about the context of when and where I meet a person," says Brian Behm, the motion design director at Rooster Teeth Productions. When he does get in touch, he can bring up the specifics of their meeting and stand out from the crowd. "It makes for a much warmer connection," he says.

4. There really is an app for that. Take advantage of the tools out there to make keeping in touch easier. Cecy Correa, director of business development at Four Kitchens, is a big of Contactually. "[It's a tool] that connects with your email and lets you know if you haven't talked to someone in awhile," she says. "It's an important step once you've collected all of your contacts."

5. Be useful. Jenny Magic, the principal and vice president of content strategy at Site Goals, once complimented a speaker after his panel, exchanging contact information in the process. A few months later, she forwarded him an article that was relevant to his panel and their conversation. When he was in town for the next SXSW, he looked her up and invited her out for coffee. "The compliment and the article link were very noncommittal way of reminding him that I exist," she says.

Email Etiquette
Yes, there are right ways and wrong ways to send an email. Knowing the difference can save you a major headache.

6. Say no to mass emails. "The first thing you should not do is send everyone a mass email," Robin says. "They'll know they're getting mass emailed and they can hit the unsubscribe button and put you in their spam filter. You'll be lost forever."

7. Know when to fold 'em. Robin also says that you shouldn't sweat it when a connection doesn't work out. Once an email has been sent, leave the ball in the other person’s court for awhile. "If they respond, great," she says. "If not, give it some time. Then send them one more email, but then leave it at that. You don't want to be that annoying guy from SXSW."

Tweet Responsibly
When it comes to staying in constant touch with everyone you meet, Twitter can be your best friend.

8. Maintain soft connections. Facebook and LinkedIn imply a strong connection, which may not be best for staying in touch with a fresh contact. That's why every mentor still stands by Twitter. "Twitter is my water cooler," Behm says. "It's my most casual connection. It's a soft connection. It's very easy to click 'follow' and check in every once in a while."

9. Make use of Twitter's tools. Don't let Twitter be a passive tool. Robin suggests creating a private Twitter list of everyone you meet during SXSW so you can keep up with what they're doing and saying. The occasional retweet will remind them you exist and find them interesting.

10. Tweet now, email later. Twitter may be a soft connection, but Magic says that it's the best way to transform something fleeting into something lasting. "If I showed up in someone's email on regular basis, it might be a little weird. I may not have enough business conversation to be inbox-worthy," she says. Tweeting at someone can lead to email, and email to lunch, and lunch to a real working relationship. "It's low commitment," Magic says. "If I tweet at someone and they don't like me or don't know who I am then they have no obligation to deal with me. Email comes with a slight obligation and that can be a negative."

Hometown advantage
If you live in a start-up friendly city, SXSW doesn't have to end with the trip back home.

11. Continue networking. Seeking out local events hosted by start-ups and companies in your area, says Paddock, and "model yourself after a great networker. Watch what the pros do." Be on the lookout for parties, demonstrations and other social functions that would allow you to rub shoulders with the people you may have already met at SXSW. By regularly attending their "office hours" at a local coffee shop, Paddock made connections at Mass Relevance before it exploded.

12. Have them come to you. Why go to someone else's networking event when your company can sponsor its own? "The networking effect isn't just getting something, but giving something to somebody else," Paddock says. "[The pros] get a lot out of their network by being generous with what they do."

Don't Force the Friendship
You've got something special on the line…so don't screw it up.

13. Patience is a virtue. Once you've forged a professional relationship, the last thing you want to do is rush things. "You shouldn't ask for stuff early," Magic says. "Let it evolve on its own." Correa agrees: "Some people are only interested in the now. They want to be your friend now. They want to be your partner now. They want to do business now." Over-eagerness can poison an otherwise strong connection. "If you have a hope for something bigger in the future," she says, "You should take it slow and try to not push for something right away."

14. Be picky. Don't confuse a crowded network with an effective one. Robin says that you should take your time selecting who you want to add to your circle since a finely tuned network of friends and partners will get more accomplished in the long run. "I wait to extend LinkedIn invitations until I've decided which people are the most meaningful to me," she says.

15. Send happy grams. Robin recalls making a vital connection on the show floor and taking her to a booth giving away free pedicures. "Since then, we've exchanged Instagram pictures of pedicures and we plan to do it again," she says. "We kept that one little memory alive throughout the year so we could look forward to meeting again in March." If you want to make a lasting impact, make sure they know you genuinely care. "Try to do something special to say that you cherish this connection," she says.