joed,
Splatter schmatter.......it is difficult to totally eliminate buffer sling so don't fret it too much.
Instead of laying down a ribbon of product on the car try placing a blob of it, about the size of a quarter, on the paint and place your pad directly on top of it and feather the trigger and at the same time move your pad in your desired motion.
It's very important to learn how to control the speed of the rotary using the trigger. Don't rely just on what speed you have set but get the feel of controlling the speed with the trigger. One should be able to set their buffer at the maximum speed and never go past the 1500 rpm range based on the sound of the buffer alone. This comes with practice.
If you do prefer to lay down a ribbon of product on the paint or lay a bead around the pad itself then you may be opening up the face of the pad too much. In other words your angle is too high. Lay down a bead of product, say 5 inches, then place the right edge of your pad directly on the far right edge of the bead. Now lift all of the pad off the ribbon, except for the far right edge, just a hair and as you begin to slowly press the trigger move the pad from right to left along the top of the bead and this will darw in the product to the center of the pad.
As you pass over the far left edge of the ribbon then close the face of the pad, or place the rest of the pad flat on the paint, increase your buffer speed and continue buffing. This method should just about eliminate any sling or splatter. It takes some practice though to learn the angle of the pad and working the trigger.
Happy Detailing,
Anthony