I also somethings do a very short (like everyone suggested, 4-8 frames) white matte and insert it above the cut in question. Long fade in, short fade out is what we're after most of the time. The advantage is that you can control to the fullest how fast and slow it comes in and out, the opacity of the white (sometimes you don't want full white, but rather some part of the picture bleeding in), as well as move it around very easily. The disadvantage is that you have to do the work yourself to figure out the length, and it takes two tracks including your footage itself.