My lovely husband has suggested we make a temporary arena for winter in one of our stubble fields using woodchip and a silage bale fence, the idea being that it will plough into the field in spring by which time i will be able to school on the grass again.
We live on top of a chalk hill...
Depends on the horse! I want them to be confident in walk trot and canter, have hacked out a bit and ridden in company first. I try to take them off for a lesson at my trainers yard first. Average of around 8 weeks for a normal horse (ie not a nutter!)
I have a Heather Moffett vogue dressage saddle and absolutely love it! It did still require some fitting and adjustment to get the balance right so I don't think they are quite as simple as plonking on and off you go.