I just plop the driftwood in, once plants have been tethered to it.
I find Malaysian and other harder woods great for this approach as they don't leach a lot and can often be bought pre-soaked (as is heavy enough to sink quickly if not).
Mopani is a stunning looking wood, but will leach a pile of tannins for weeks and also grow white wood mold, which is pretty much harmless and great shrimp food - I keep a few RCS or Darwin Algae Shrimp to keep the mold down, and have never had a single issue other than that in using the wood with nothing but a quick hot water rinse (you Americans -need- to experience the algae munching powers of our native Aussie shrimp! haha)
I love the tannins, so do the bettas - who also love snacking on the shrimp, who in turn love snacking on the wood mold. Fish and shrimp are all fat and happy (the shrimp don't really enjoy being snacked upon, but anyway..), so I don't feel the need to boil the heck out of the wood.