Egress Window In Basement.

[pushkins]

Looking good, your on the home run now.
If it were me I'd apply a bead of caulk to the trim where it touches the cinder blocks as well. After you have nailed it and it dries come back and add one more bead to the very edge of the trim against the cinder block just to make sure you have sealed it off and it makes it looks pretty.

[DKAudio]

Thanks, what about the edge of the trim on the window side, caulk there too?

Should I make 45* cuts or do it like J channel would be done...

Thanks!

[pushkins]

If your house is "Craftsman " style then you'd just put one over the top and the verticals would just but up to it, otherwise I'd miter the corners.
Yes put a bead of caulk on the window side of the trim as well.