Lesson learned, you absolutely can not get good use out of a FEL without the proper amount of ballast/counterweight. Even with loaded tires, I usually use something on the 3PH.
Agree keeping bucket reasonably low is a good idea, but even better, don't get greedy and put too much weight there in the first place; easy to do with wet dirt/mud. As per BeezFun, make sure you are balanced well before moving and if not, drop/add weight to come into the proper balance.
Even when properly balanced, you can still roll, so do some reading on old threads and tailor your use to your level of experience as your skill confidence builds.
nebraskasparks has some good threads on rollovers/slopes etc as do some others.
One last thing, no matter how long you do this or how good you get, it can still happen so never get complacent and always have a strategy to abort or mitigate the effects.
. There was no time to react... I could not believe how quick and easy it is roll this thing.
Probably everybody on this board has had the same wake-up call at one time or another. My lessons learned were always get the bucket as low as you can as fast as you can and keep keep your hand on the FEL control and be prepared to shove it forward.
Also, on wet ground, at any kind of a slope, it will slide down the slope really easily. Have it in 4wd to get maximum breaking ability.
It is somewhat embarrassing to admit this, but I nearly rolled over my still new b2320. I went out right after heavy rain to move a pile of dirt. The ground was soaking wet and after moving a few buckets, a slight rut developed on the right side of the tractor... Right where the back wheel is. I did not have my backhoe attached so the tractor was light. In a split second while backing away from the pile with a full bucket, the tractor rolled right after biting the rut. There was no time to react... I could not believe how quick and easy it is roll this thing. What saved me is kind of funny.... While the tractor was rolling to the right my shorts got caught on the loader control stick.... Somehow my pants pulled the lever down and the bucked dropped quickly.... I sat there maybe for 10 minutes going over and over what just happened. I guess I am lucky to say that I was saved by the seam of my pants. Lesson learned: I will not lift stuff without a backhoe for added weight and stability. A weight box or filled tires will also be considered.