The real key to successful soft-proofing, apart from making a good custom display profile, is the parameter settings. If working in a dimmed room, setting the display luminance to a range of 90~120 is important for simulating the appearance of a print made on good quality luster/gloss paper. While it has been questioned, I find the L* contrast curve works well. I white balance to D50 because for my visual perception that matches closest visually with the Solux 4700K bulbs under which I view the prints. I should acknowledge that these settings are often the source of much disagreement between highly knowledgeable and experienced people, so best experiment around these values and see what works best for you. I'm just making the general point that good calibration of these variables is essential to success with softproofing in terms of reliably predicting what the print will look like. Also the "make my print look like crap button" (Simulate paper white checked ON in softproofing) is really important for matte papers but still useful for luster/gloss papers too. No point fooling oneself at the display stage only to be disappointed at the print stage.
