You scale the image, first, then use CFIMAGE action="writetobrowser" to display it.
So how should it look then?
According to Adobe CF docs, resizing an image is done as:
<cfimage required action = "resize" height = "number of pixels|percent%" source = "absolute pathname|pathname relative to the web root|URL|#cfimage variable#" width = "number of pixels|percent%" optional destination = "absolute pathname|pathname relative to the web root" isBase64 = "yes|no" name = "cfimage variable" overwrite = "yes|no">
Then, writing it to the browser is like:
<cfimage action="writetobrowser" source="#image name from first cfimage tag#" format="gif" id="yourID" />
UPDATE: I just noticed ImageScaleToFit. Sorry. Place the following between the first two tags I wrote:
<cfset ImageScaleToFit(image name from first cfimage tag,options)>