Does anyone have a recommendation?
Yes. Forget what the book is telling you about shift points. Go about it in a slow, deliberate manner. Don't wind it out, it's not a race car. In fact, just barely get the thing rolling into the RPM while not going so slow as to having it lug the next gear. You will find the RPM range that suits your ability on your own. Once you can do it smoothly at your rate, you should have a sense of the intervals between the gears. You also need to have a sense of the time it takes for the engine to wind down from various RPM. Going faster can make for a smoother shift but it won't teach you anything.
It is NOT the same RPM drop for each subsequent shift, particularly, 1-2 and 2-3. If you can get a feel for that, you will be well on your way towards losing the amateur status. (No slam intended).
Don't dump the clutch peddle, use a two step approach to the pedal release.
First step takes out the slack.
Second step, with a little more finesse than taking out slack, smoothly transitions to full engagement.
Blend those two steps together for a single fast-slow motion.
The jerking is mismatched throttle. Tell your right foot to STFU until it knows what it's talking about.
The goal is matching RPM between the engine, the gear and the road speed. Then you can do clutchless shifts.
Your feet aren't the only adjustable variables. Cold transmissions don't want to shift. Allow them the courtesy to warm up before trying to force the shifter, which means, your hand is also part of the equation.
Do it all deliberately at a relaxed pace, both you and the Jeep.
Going slow = Smooth.
Smooth = Fast.
Gotta go slow to go fast.