Find a crack and wedge it in. That's what I did. Works perfectly, and you don't need to worry about threads and knots.
Also, re the driftwood - depending on what type it is you'll have to soak it for a while. Some wood you buy is very dusty so make sure all that is off. soak until the water is a bit clearer and doesn't instantly go darker. Leave it overnight a couple of days if you can. I never boiled mine and left for 2 days.
If you get fed up though, remember that the tannins in the wood will not harm your fish or plants. It's all natural and in some cases, some fish and plants can thrive with slightly coloured water from the wood.
If you're really lazy, do what I do and buy the drift wood from the lfs display tanks. they usually sell it to me cheaper, and often you get freebies like java moss, eggs etc... and once, I had a cheecky stow away fish that attached it'sself to the bottom. (plus if it's for a new tank, It'll have established bacteria for you)
