Well I move those disc in some to form the bed. I have one of those hand roll sod rollers that is clamped to the tool bar at around 8" from the ground. That what seemed to work for me.
Doing it over, make it longer, use smoother type tires. I would still have my tool bar removable because it is used for other things.
When I enlarge my garden, I'll probably buy one already made. Can't remember where I found one for around 1200.00.
The plastic cost is somewhat high and then there is the irrigation stuff. But in my case, one 80' row with 36 tomato plants yielded more than 200 gallons of green ones, then when the cooler days set in there were about 60 gallons of green ones. Very little weeding, very little watering but a lot of picking. I watered about once per week for about 1--1 1/2 hours.
Here in central Oklahoma, just after everything was established, the rains came in and washed 1/3 of every thing out, so replanted, repaired and went on. The neighbors down hill had corn, tomatoes, squash, little bit of it all growing in their yards. What a deal !!!