I usually pause when I find a collectible, then drag 4 kids (if available) close to it. Once I have them there I place one on the collectible while paused, then pick up the second kid, pump the spacebar twice quickly to repause, drop the kid, pick up a third, pump twice quickly, drop, and if I'm lucky, pick up the 4th, unpause and drop quickly. 6000 Tech points in a hurry!

Most times I only get 3 tho