A long time ago, when I started learning on a bait caster, there were a few articles here and there in fishing magazines, but I really didn't have a teacher or much instruction, I had to figure it out on my own.
Coming from spinning gear, as my spinning casting skills improved, I was more and more able to deliver "line drive" type casts, straight to the target.
Casting with bait casters, you've got to lose that "line drive" mentality and visualize your casts in curves and arcs. You have to learn how to feel the rod loading. If the rest of your casting process isn't in synch with the rod loading, backlashes will happen.
A switch to straight handle rods was a blessing to me, because it let me cast with two hands easier. For me, especially in overhead casts, where I am going for distance, two handed casts are critical.
For me, the instant you feel the rod want to go forward, it is a coordinated push/pull/ thumb release movement.
The back cast loads the rod. (two hands make a sharper, more forceful back cast ) The instant you feel the rod want to go forward, you help it, by pushing with your top hand and pulling with the lower hand, thumb releases the spool, and if done correctly, lure sails in a modest arc out toward your target.
I don't know how to explain it any better than that. With the exception of pitching, where I start out with one hand on the rod (with thumb on the reel) and my other hand holding the bait, most of my casting is done two handed, using some variation of the push/pull motion. You can do it sidearm, three quarters more or less over wither shoulder, directly overhead, whatever.
Some rods are easier to load and to feel than others, but the principle is the same no matter what power or action of rod you choose. At this point I think that you just need to practice some in the back yard and find a technique that works for you. Buy a bulk spool of cheaper mono and you won't feel so bad about backlashes. You are going to get back lashes in the learning process.