A way to get good results would be to take a number of sequential shots of your subject, since a slight change in your posture could throw your intended focus point completely off.
I've always heard this referred to as "poor man's IS." Take a burst of several shots, and chances are good that one will catch you at the apex of your shaking.
Without implying that the 85L is anything other than a superlative lens, I have to put it alongside the 50L as Canon's two worst value lenses. Both the 85 f/1.8 and 50 f/1.4 outperform and often outright spank their bigger brothers in all sorts of ways more important for 90% of photographers, and there's very little the L lenses can do that the non-L counterparts can't.
Unless you actually need that extra half a stop in either case -- and damned few people do -- these lenses are a waste of money.
Of course, for those who really do need that extra half a stop (and, yes, there absolutely are those who do need it), or for those for whom a couple grand is pocket change, it's either a smart investment or a no-brainer.
But almost everybody else is better off in every meaningful way with the non-L versions.