Bobbers or floats can be very effective for targeting muskie when they are in the shallows. Make sure to use a big enough bobber to be able to handle the large bait fish that you will be using for muskie.
When you need to get down deeper with your live baits, try using a slip bobber. You have a lot more flexibility for changing depths as well with the slip bobber, so it makes it much easier to fish shallow, deep or in between.