Finish the Glass (8)
Now sizing the block accordingly using course paper block the filler to contour, as you get down close to finish height switch to the 220 grit paper and feather edge to contour. You should not be able to feel where the glass stops and filler starts. The smaller spots can be blocked with only 220. Don't be surprised to see a low spot in any larger filled areas. The putty knife will often drag along enough filler to leave a low spot. Often it takes a second coat to bring these areas to contour. Scuff the low area with 100 grit before adding the second coat.
Tip: If you've applied filler to match a door/fender or body/bumper gap contour, apply masking tape to protect the unfilled side as you block filler to contour with course grit. Remove the tape when blocking to finish contour with 220 grit.
Photo shows the front bumper to fender contour with second coat of filler. If you look closely you can see the previous filler lines about the middle of the marker light recess.