The space next to the railing is cramped, making it impossible to wrap the chain around the frame. So instead, I wrap it around the bicycle's rear wheel. If you are familiar with classic Dutch bikes (full chaincase, dressguards, bolted rear triangle), you will know that removing a rear wheel on these babies requires tools and takes about a half hour - so locking up this way is not much riskier than chaining it through the frame. I also put a cable lock through the frame and front wheel (the cable lock goes with me when I take the bike out). While no lock-up method is 100% secure, I feel comfortable with mine. I weighed the utility of this arrangement against what I perceive to be the risk of theft, and to me it's worth it.
It is not my intent to suggest that everyone ought to keep their bike outdoors. Judge for yourself based on how much extra utility you think you would get from that, as well as how comfortable you are with leaving it out. If you do decide to go that route, I suggest a good chain, a plan for saddle protection (it will rain if you leave it uncovered overnight!), and a lock-up ritual that does not end up being too fussy and time consuming. Do you lock your bike outdoors?