I didn't do any tick tock photos of the the first stool drill and fit of the mortise and tenons. Did a little today on the second stool.
After shaping the legs I marked out the position of the mortises and the sightlines on the bottom of the seat. Once marked I drill the mortises. The first step is aligning the sight line with references. I like three, the location of the mortise center, a mid reference, and then a far reference.
Next I aline the center of the brace with the other two references.
Then check the resultant and start drilling. I will stop and check the sightline and the resultant every two to four turns.
Last a photo of the legs dry fit to the seat.
The tenons on the legs are very easy if you have a lathe, get 'em close on the lathe and then use a hand held tenon cutter for final fitting.
Next up is shaping and cleaning up the seat, sawing slots for wedges in the tenons, and then a little hide glue and knocking those suckers home. Once the glue dries trim the legs so the seat is level and put some finish on. More than likely Danish Oil because it cures quickly and I do not have a lot of time.