Masking techniques

Have you tried putting a piece of masking tape over the individual frame, press down a bit then use the side of a pencil point to expose the frame edges on the tape. Remove and stick to a clean piece of glass or ceramic tile then trim with a sharp #11 blade. Way easier than running thin strips along the edges.

Thanks much folks, that's just the info I needed. Perfect.

For liquid mask, I'm using Bob Dively's Model Aircraft Liquid Masking Film.  Might not be the best choice for masking along the edges of window frames though, because its really difficult to get a crisp edge with it.  A Tamiya Masking Sticker sheet would probably be better for that.  I used one recently to mask the glass panels in the front of the Sniper ATP pod I put on my recently completed F-16, and it gave me nice, crisp, red edges on the glass panels.  Those panels are pretty small, and the masking sheet material is extremely resilient...but also easy to cut.  The adhesive on the back hangs on nice and tight, even after peeling and sticking a few times to get the positioning right.  On a larger area, you can use that to mask along the edges of the frame, and use the liquid masker to fill in the large areas.  Its pretty much the same kind of stuff that Eduard masks are made of, as well as the canopy masks Tamiya includes in a lot of their kits.

I use vallejo liquid mask and find it great stuff for masking... Use silicone painting brushes(nail art brushes) to apply as it will destroy ordinary brushes  just peel off the silicone brushes when dry...