Some great advice... I'll add a bit by comparing limbwalking to roofing. Walking a 4:12 pitch roof is easy... but as the pitch increases, it starts to get sketchy. The type of soles on the shoes/boots you're wearing only get you so far... as you hit around 8:12 pitch traction gets iffy, and at 10:12 you aren't going to walk it unless you get assistance. An anchor at the peak and a 3/8" rope will magically make it very much easier. The rope won't stop you from hitting the ground if you fall off the roof, but you would be shocked at how just holding onto it for better balance makes a 9:12 or 10:12 pitch roof easy to maneuver around on. You barely have to put any weight onto it, at all. The same is true with limbwalking... if you can get your climb line off-axis to the limb and use it to balance, you only have to put a little of your weight onto the rope to make it easier to maneuver around. Of course, the steeper the angle of the limb, the more weight you'll have to put on the rope. A long lanyard or second climb line that's anchored out near the tip of the limb you're walking will help you to move up and out, as well as giving you two lines to use for balance (much steadier and safer). As others have said, instead of trying to balance yourself plumb to the top of the limb, you walk a little off to the side of it. When you get way out there, you can use the two lines to actually hang out from, and a bit below, the limb to make your face cut. I lanyard in, as well, once I'm in position. The triple attachment points make it pretty hard to accidentally cut yourself loose from the tree, and it has a nice, solid feel for when that weight drops off the limb and it bounces around.
