If the tight trees are offset you try to approach them a little to the opposite side of the trail from the first tree you could hit so to give more handlebar clearance. This also actually provides more distance between the trees once you commence to slightly steer through them. Once past the first tree you just quickly flick your bike back the opposite direction to clear the next tree trunk and to maintain good forward momentum. When the trees are parallel you definitely need to approach with the front wheel to the side of the trail to attain a better angle to perform the wiggle through that smaller trail width. Plus this helps you to miss any nasty bumps, exposed tree roots, or deep ruts that will likely form there from other riders having to do the “stop and start” method.
Unlike what you probably read on an internet forum (ha, ha!) you don’t wheelie and turn the handle bars through tight trees like this as it is actually way slower and much more dangerous than doing the “Wattsy wiggle” through them, unless of courseit is a very unique situation where a decent sized braking bump has formed before the trees and you can then jump through the trees with the hangers turned for decreased width.
Depending on the stiffness of the trees many times you can just blast through the smaller trees without even turning your bars unless it is a Manzanita bush or some crappy tree like that.