I will be using this 3D object that i've modeled for this tutorial. Notice the top section requires a boolean subtraction operation while the bottom requires a union operation.
P.S: There's no one way of modeling this object, its just that for the sack of this tutorial, I'll be concentrating on boolean here. This is not a step by step tutorial on how to model this part, just how to fix boolean in 3DS Max which is why you're here for
Create the overall form of your object and its boolean counter parts
For inferior works, this should suffice, but why do I even say that?
Nobody wants these! Not even nobody!
This is the steps to fixing the boolean. You may want to note it down or something
1) Remove isolated vertices, meaning vertices that do not connect to any edge's end point.
2) Now connect the vertices together so that the edges flow "nicely" using the "target weld" function.
3) Now try to make all the surrounding polygons four sides, if that's really not possible then five sided.
P.S: Resist creating three sided polygons. They give a horrible pinching effect when weshSmoothed.
The ideal result.
Here are more examples of nice wireflow that result after fixing boolean operations
Just look at how well those fixed boolean intersections flow in and out after meshsmoothing. Just look at how those curved edges catches highlights!