Aside from all the great tips from Nightflower, there is one thing I would add to that list. For me, the key factor in maintaining balance between two worlds is transparency.
I think it goes without saying that balance for most of us lies with our real life responsibilities on the heavy end of that scale. But the allure of escaping problems in our lives to a pretend virtual world can be consuming, and it is one I too, like many others, have struggled with.
There was a time that I tried to keep my SLife a secret from my husband and family. I won't bother to go into those details because honestly, we've all heard that story before, so there is no need for me to repeat it here. I'll just skip to the part where all the energy I invested into compartmentalizing my two words and trying to keep secrets led me to cave under all the pressure I imposed on myself. Things reached a point where I seriously considered walking away from not only SL, but my marriage as well - due to longstanding issues that existed way before I created my SL account. I know what you're thinking, everyone says that, but what can I say? That's the truth.
I'm happy to say that I didn't do either of those things.
Instead, I took my power back into my own hands and I made some choices. I chose to work things out with my husband, which seemed like a lot of work at the time, but within a few short months, things started to turn around dramatically.
I chose to stay in SL, but I knew if I wanted to do that, I had to shift my reasons for being in SL from escape and avoidance, to something that had a positive influence on me in my life. That's when I started getting consistent with updating my blog. I started commenting on other blogs that I liked. I joined Plurk and I started making new friends. I tried new things in SL like modelling - which didn't turn out to be my thing, but it was fun while it lasted. Just like in my real life, I made new choices and in the months that followed, I started seeing and feeling big changes in both my worlds.
The key thing for me in all of this is honesty. I don't keep secrets about SL anymore and that feels infinitely better. My husband, although he doesn't completely understand SL, gives me my space. Besides, I'm not interested in watching 4 hours of Euro and Deutsch World news with him every evening (nothing against Euro news, I just think one hour of news is enough lol). One of the great strengths of our marriage is that we have always felt good about giving each other the space to be independent and pursue our own interests. And to be fair, he did give SL a try and we created an avatar for him. Being a musician, he is interested in the music scene, but his work schedule is all over the place, and the bottom line is, he's just not that into SL. And that's ok.
My activities in SL are free for my husband and family to take a peek at, however, they are not really interested in it anyway, which is fine by me. My point though, is that if they wanted to come take a look at what I'm doing, I have nothing to hide. Keeping SL a secret only implies that there is something inherently wrong or bad about it, and that's not the message I want to put across to my husband and children.
Another seemingly small thing that I do that helps me maintain balance - I have loosened the reigns so to speak on my boundaries between RL and SL. I have my RL pic in my first life profile, I keep in touch with my close friends over Facebook and email. These are things I never would have considered doing before, but I feel safe to do this now because I don't have anything to hide anymore. And one big thing I have learned in SL is that all people really want is for you to just be yourself. I realize that you don't need to post your RL picture or disclose personal information to be yourself, that's just my choice.
I also have a career that I love, a mortgage, and my two children (who are my world), that keep me grounded in the atomic world. Yes, my children are often around when I am logged in (which explains my random afk's), but they are my first priority always. I would much rather be out in the world with my husband and children than logged into SL. I think I have been here long enough to pass the consuming addiction stage and move into maintaining a comfortable balance between my two worlds.
For myself, transparency between two worlds is the bridge that connects SL and RL. I know others may not agree with this, but everyone has different lives and circumstances and in my case, I know this is the right choice. I am not suggesting that this is the right way for every single person. This is only what feels good for me. I suggest that anyone who is struggling to find balance, to be really honest with yourself and have the courage to find what feels good for you too. One thing I know for sure is that it will not be the same for every person.
When I am open and honest about SL with my husband and family, and most importantly honest with myself about what needs SL is fulfilling for me and why, balance just seems to naturally fall into place and doesn't feel like much work at all.