You can start at either end. The bottom is preferable if you enough tractor to dig easily. I have to work from the top down to give my Toy Tractor
the help of gravity as it's quite small.
Use the bucket and establish a level area, then dig and side dump making sure you keep the working base level side to side. Finish off with the box blade. Use caution as you side dump as you do not want to go to far forward and over the lip.
This is basically how a dozer with angle blade would do the job on really steep side slopes. It can be interesting to see one have part of the slope fail and he goes for a hundred foot or so slide down the hill.