1) DONT LET YOUR GUARD DOWN - just because you "have" a girl, doesnt mean you stop gaming. Her attraction to you is something that needs to be constantly maintained. Hold your ground, be sexual, be dominant, be the leader. You should be someone that she respects. dont let her walk all over you in ANY way. She wants to push against you so that she can feel you holding steading and keeping her in check. this is sexy to her. She will keep testing you, probably not as much, but just be aware.
Also, don't let yourself get rusty. Game other girls as far as you're allowed. Im NOT saying to cheat on her. Obviously kissing other girls, getting their number with the goal of going on a date, sex, dating other girls is all off limits. However, you can keep practicing indirectly opening other girls, keep working on your body language, mild kino, etc. An innocent way to stay sharp is open attractive girls in public places and just mildly flirt with them and make conversation.
2) BE GOOD TO HER - i'm not saying to get all mushy on her. But be a good boyfriend. Entertain her, embrace her, respect what she has to say and pay attention when she is talking. Don't cheat on her.
3) DONT FIGHT - this seems like common sense...but each time you fight, a small part of your relationship is chipped away that can never come back. I'm not saying you can't confront her or chew her out..But if she's just trying to get a rise out of you, stay calm and be the one that dissipates the argument before it comes to fruition. Sometimes you get frustrated with each other and you both feel like fighting.... resist this urge. I'm not saying to concede to her or admit she's right.
4) DONT LIE - it's very very easy for even a small lie to come back and bite you in the ass. something as simple as her asking you how you know a certain girl, or how many girls you've slept with can get you in a load of trouble if she finds out you fibbed. I like to be COMPLETELY honestly with a girl i'm dating. That being said, if theres something you dont want to tell her, you can avoid the question or give an ambiguous response..
5) Be prepared to have girls throw themselves at you - it's torturous because once you are in a relationship, girls that dont know you can smell a) you're getting laid regularly b) you're indifferent/non-needy because you already have a girl and c) you're preselected. Dont put yourself in situations where you are tempted to cheat. Try to bring her along to parties, and if you go out drinking without her, make sure you keep your drinking in check and keep ful control over yourself.
6) GET IN WITH HER FRIENDS - no, i dont mean hookup. One of the best things i ever did was become very close friends with all of my girlfriend's roommates. They were actually cool gals anyway. But if her friends love you: a) they will pull for you and tell her you're a good choice, and b) if she is EVER in a situation where her friends are there and you arent and she is tempted to cheat on you, her friends will do everything in their power to prevent this if they like you.
7) KEEP THINGS INTERESTING - you cannot allow yourselves to grow stale and fall in a routine. Change things up, keep her on her toes, constantly excite her. Go different places, travel, make a conscious effort to keep things interesting. Especially when it comes to sex. Randomly throw her against a door and grab the back of her head and make out with her. Try out different things in bed.
remember: if the relationship gets boring at any point its ALWAYS YOUR FAULT. even if it's really her fault, it doesnt matter, its UP TO YOU to keep it interesting or she'll rationalize that you didnt care or werent interesting enough.
8) STAY FOCUSED ON YOURSELF - we all know the guy who drops everything when he gets a girlfriend. Dont be this guy. Maintain your hobbies, keep working out, make time to hangout with the guys without her. She is not central to your existance. She is peripheral to your goals of improving yourself and building your career/life. When i got into a LTR, my schoolwork and hobbies suffered. Dont let this happen. She doesnt want a guy who drops everything to be with her. It's fine to let her know that you can't hang out with her EVERY DAY of the week. Take a day now and then away from her to make sure you guys dont see each other constantly.
I'm not an expert by any means, but i hope my limited experience is helpful. It's always irritating how much pickup if focused on getting the girl rather than keeping her.
