[Cob] How to get a straight wall with cob?

[Amanda Peck]

It gets better as you keep mixing.

Although when we did my floor, a friend who described herslf as the 
"Oklahoma mud-pie queen" when she was a kid, got it right easier than I did. 
  She did a lot more energetic mixing before and after we started putting in 
fiber than I would have.  So don't expect a good answer for me on the first 
one, although pure clay might be too smooth and plasticky.

And a drier mix won't slump as much.  And/or less put on at a time--in 
"cobs" rather than as a huge mass.

The way to get a really really straight wall is to put it into slip-forms.  
You don't want to do that.  Modern cob is based on free-flowing shapes.  ;-)

You do want a slight taper from bottom to top of the wall.  I've seen a 
tapered stick attached to a level used to measure this.  How to measure, how 
much taper (and inside, outside, or both--some of this will be personal 
preference) may be in Becky Bee's book (which seems like the good one to 
have with you when you work).  and you can bash it into shape with that or 
another stick (2 x 4 [inches--around 5 x 10 cm], used longways can be used 
to pound out the worst of the slumps and bumps).  And if it was really too 
wet, it will still be bashable the next day.

When you can walk on the wall it's dry enough to put another layer on it?  
When--ideally just before--it starts slumping is when you quit for the day?  
Someone who's done more of this than I have needs to answer all of these 
questions again!  And think about how you are going to get your layers to 
bond together.
................
Bob and Lorraine had trouble with their first cob mixes--so Lorraine wrote:

Today we started our first cob wall.  It's brought us to some questions
I hope more experienced cobbers can help me with.

What should a good mix look and feel like?

Ours was patchy with some parts of it having a smooth, plasticiny feel,
some lumpy/gritty although wet, and some being a bit dryish and rubbly.
We tried various methods - forking whatever we came to onto the
foundation and patting it into shape, pressing it into cobs with our
hands then incorporating it onto the wall, and doing more mixing in the
mud pile before forking it onto the foundation.

How do you ensure that the wall is straight-sided, not rounded down at
the edges, and that it does not gradually become narrower as you work
upwards?

How do you manage to walk on it without causing it to bulge at the
bottom? (We didn't try)

How high can one go in a layer, and how long should one leave it before
adding the next round/layer?

Do you have any suggestions to make the job better, safer, quicker, etc?
Any suggestions and ideas would be most welcome.