I call jumps like the ones you describe 'step-downs'. There are also 'step-ups', where the landing is higher than the take-off.
Step downs are generally easier because your weight is centered over the board on take-off, you don't have to adjust much.
On regular kickers (because the 'kick' you up) are different, you have to change the your body position from and upwards angle to a downwards angle.
Most people don't really think about it, it just comes with practice. A good way to get comfortable with it, and the most basic form of jumping is the ollie.
Practice your ollies, popping off the tail and landing with both feet at the same time. Just practicing that means that you have to shift your weight in the air (from popping off the tail where you have to weight your back foot, to landing centered over the board with both feet means you have to shift the weight from back to front), almost the exact same as on a kicker.
So get your ollie on, practice it off of small bumps, over small children, and lava puddles.
Then take it back to a kicker, with out actually popping off the tail (you can if you want way more air, but its not neccessary).
King Shit of Turdville