For many years, I've assembled a Christmas presents wrapping mix CD for my family's Thanksgiving get-together. Each year, while assembling the music, I've had to stop myself from listening to various chosen carols back to back and thinking, "Yeah! That flows! Let's hear those again...and again...and again."
The time to revel in a mix CD is after you've completed it. Congratulating yourself too much while you're assembling it is ill-advised and stalls the momentum you've established.