Hitch hiking on Jim's and Travis' input I have always done well with size 14 BH soft hackle ant. Red abdomen, black thorax with grizzly hackle. Another proven (for me) is a size 12 butcher. Red body palmered with black wet grade hackle. Since I can feel better than see I skipped the strike indicator and go with leader no longer than 7'.
I don't think the fly is as important as finding a school and getting a good presentation to them. Then they can be a little difficult to hook since often the bit is very quick and you don' have much time for a hookset. Just like reading water for trout or steelhead, they definitely have preferred holding water and that is the key to catching them.
I catch a lot of whitefish in the winter with a Barr's Tung Teaser ( I like a size 14 ). Any beadhead fished on, or close to the bottom will most likely catch a few fish. For the last couple of weeks egg patterns have fished well on the Crooked and Deschutes Rivers here in Oregon, egg patterns will fish well until late January. I believe the key is to get your fly deep in the water column.
I use this fly (bottom photo) because when it gets wet it looks like that (middle of top photo) which resembles these bugs (top photo), which are a favorite snack of Klickitat River whitefish. This is a size 10 hook and matches the standard size skawala stone very well. Unfortunately the Klickitat River has a size 14 hook restriction now, but this fly in a 14 is still a whitey killer. Tom