Here's a technique I posted elsewhere some time ago. It's still my standard method.
I use a Rubbermaid washing up tray for sheet film development. It's a fraction over 8x10 size, sculpted bottom, rounded corners, and six inches (no splash, no spill) deep.
Agitation is a slippery variable so I decided on continuous agitation for all films. It also gives me something to do because some of those dark minutes and hours can seem to drag. The agitation sequence goes like this:
Slide the film quickly into the developer face up.
Lift the front edge of the tray until a wave of developer travels to the back. Lower the front edge and wait for the wave to return to the front. You can feel the wave because the tray sends the changing force to your finger tips.
Now do the same with the right edge of the tray, then the back edge, then the left edge, then return to the front. Keep going until the development time is up. If you are really fussy turn the tray through 180 degrees half way through development.
This system gives me perfect, even, scratch-free results for all films. The down-side is a one-sheet-at a-time system means time, tedium, and labour. But I don't care. Large format photography is playing for high stakes and I'm not going to carry a 4x5 or 8x10 all day and then botch film development because I was in a hurry.
Chasing smooth even skies is not always possible because the sky itself can carry surprising tonal modulations. They are hard to see because the sky is so bright but film will surely find them.