patrick wrote:
How does foam board attach? I assume that is the blue colored board?
I would think the foam might be the most effective, but I can't install
it myself.

The foam board can be attached almost any way you can think of - nails,
screws, adhesives. You can cut the board to make a wedge fit between
the joists and use a can of expanding foam to seal the gaps.

Which is then more effective--the foam board or fiberglass?

Rigid insulation has roughly twice the R-value of fiberglass batt
insulation.

I don't understand the comment about making the basement colder, this
is above a closed off crawl space.

The heat coming from the room above the crawlspace won't supply enough
heat to heat the basement to any measurable degree. It's not a factor.

R