If you're a jeans person, buy a great pair of jeans that fit comfortably, maybe even on the loose side. (I think someone said that already.) I hate hate hate the feeling of my tummy being squished. I eventually realized most of my grouchiness about gaining 5 lbs was just physical - my jeans were uncomfortable. Of course, jeans shopping can be its own special hell.
In terms of Jedi mind tricks - I think so many of us judge ourselves so differently than we'd ever judge others. Not just that we're more compassionate to others (though we are!) but that we actually see ourselves differently. We get so used to our own shape/size at an earlier time that when it changes, it just feels wrong. But a stranger meeting us for the first time would never have any reason to think it looks off at all. So if you can somehow manage to view yourself like other YLF fabbers do, you might be more inspired by your clothing.