Took me nearly a year of playing lol. But we restarted our server this Monday to start from scratch and it clicked. I was chopping down the normal trees outside our base in the meadows gathering us some wood and inevitably the falling trees knocked over birch as well. So I thought if I push the birch logs over to some more trees I might be able to get more to fall on them and break em entirely.
So I start with pushing a half log and accidentally run it into one of the fallen regular logs. And smash! She breaks into 6 pieces of fine wood. So I spent a while just repeatedly rolling any fallen birch I had into other logs. Into each other, into other trees, rocks, whatever. The rocks won't do any damage to them. Also they seem to just smash right through stumps. But other logs? Hell yeah. Log on log action will eventually bust these bad boys open. Got me a fine wood bow now before we even started tackling the damn black forest.
Maybe some of you all already knew this trick. But it's a effective way to get that bow and some home decor a little early! Make hunting them damn deer for your leather gear a lot easier!
Source: https://www.reddit.com/r/valheim/comments/s7rl8j/found_a_good_way_to_get_some_fine_wood_early_on/