Seeded some hay this last spring into canola stubble. Used wheat as a cover crop. Broadcast the hay/forage seed on after and harrowed twice and then rolled it. Seemed to catch from what I saw in the fall.
Works good after canola. Did some last spring and cultivated one pass ~1" deep just to knock off the ridges left by the drill and fill in some ruts etc. Seeded with a single disc drill at 1/2". Seeded 11 lbs of 90% alfalfa 5% timothy 5% meadow brome with 30 lbs oats cover crop. Oats stooled out and had a fair bit of volunteer canola. Was too much competition. Had good moisture and looked like a great stand after silaging it in the fall. Wouldn't do the cover crop after canola with the amount of volunteers.
Before no-till we would work black then broadcast and harrow and roll. Worked good too.
If there's enough moisture any old way will work for establishing grass. If it's dry that's a whole different story.
This may not work for everyone but this is what I have found works best for me. The year prior to seeding a forage I like to use edge. So peas canola lentils any crop like that will work. The edge will have worn off enough the next spring it wont hurt the grass you seed but will stop millet and a good portion of the wild oats. I found broadcasting the seed in front of an air drill works well. Seeding oats or barley for green feed works best I find. I don't harrow usually just roll after I seed. Cut the cover crop early for green feed . This gives the grass a chance to start growing with no completion. works well for me.
No need for a cover crop. Usually enough wild oats for a cover. We used to valmar on grass seed ahead of our new noble seedovator then harrow pack after. Always had a good catch. This year I'm going to zero till with our pillar disc drill. I'll put some fertilizer down too. Depending on how weed growth is I can leave it, bale it or silage it. I'm planning alfalfa and hybrid brome.