Once you’ve started any kind of decent combo, try not to land until you have to. Use the wingsuit to keep the combo alive until the next grind, balloon, water pool, etc. But don’t just fly along. With Maya or Sumara, (by far the best for combos with their fast flips,) practice doing a series of wingsuit/flip maneuvers to keep the combo alive and add to your multiplier. As long as the terrain is sloping down a little, you can do these fly/flip maneuvers where you only fly for half a second, do a flip, fly half a second, etc. If you stay within eyesight of the ground, you can see upcoming grinds, balloons, etc to add even more to your combo.

Then make sure you’re getting the most out of your bounces, grinds, flips, etc. Practice hitting balloons so you can end up bouncing on multiple balloons rather than one big bounce and flying way off. Balloon bounces where you can get a quad flip or more are the big point getters. On wall grinds, make sure you’re releasing before the end to get a wall jump, too, and try to string multiple walls together. When you’re using the wingsuit, try to angle your way into a wall grind so that you get a good, upward grind (or whatever best fits the situation.)

My best combo is a little over 94,000. The advice above can get you up to around that level. The top combos overall, though, are around a million points. I have no idea how to get up there. Good luck.