If you have access to a boat, there is a wonderful source for free driftwood at many lakes. Wood that is under water and then out and back under over many years gets a pretty special treatment that makes it fit what I like. Fallen wood found in most woods, etc. tends to get bugs and decay so that it may not be usable. Wood that is in/out of the water does not get the bugs and decay that makes most wood rot. Harder to come by but much higher quality and definitely cheaper!
i find nice drift in rivers or lakes, ponds and what not. also *** just put fresh off the tree branches in my tanks haha if your have any kind of wood eating plecos theyll love it! my clown plecos will sit and nibble a fresh branch every day all day. and it looks good and natural. some people even leave the leaves on there.