Bury it in the ground before decomposition, not that hard.
* You produce biochar, which is almost pure carbon, and therefore you are only sequestering the weight/volume of the carbon, not all the water and other stuff.
* Biochar can be used as a soil amendment to improve microbial cultures and store carbon for hundreds or thousands of years
* You can produce energy in the form of heat or wood gas
* You can produce wood vinegar, which may have some agricultural or industrial uses
I think there's a nascent industry in converting biomass into biochar and sequestering it, but it would be very interesting to see it done with forestland more generally.
To expand on that, biochar seems to be the majority of carbon removal delivered commercially to date:
Of course the entire CDR industry is nascent.
Bio-oil via pyrolysis is another option. Charm Industrial is trying to scale that up.
I've looked at pyrolysis for home sustainability and have yet to find a good set of resources for it outside making charcoal.
Where's a good place to read up on it with an eye to practical applications ?