Once you get the other areas, you only need two shrink "towers" in the first area, one on top and one not on top (I use one on top in the middle, one on bottom), and take the range and double targets upgrades.
early game, I only go one on top and one on bottom, take the range upgrade, save up for the double-target upgrade. Then it doesn't matter too much after that. Probably hit prestige asap to get the faster ball drop.
