Persistence will be the best tactic you can use. Other than that here are a couple of thoughts.
Use camo... snow camo or white coveralls will make a BIG difference in how close you get and how many bunnies you see.
If the snow has all melted and the rabbits are still white it's gonna be extra tough. They're vulnerable and they know it.
Early morning and late evening can be VERY good.
Learn to read a rabbit track and get after them right after a fresh snow. Lots of fun and increases chance of finding one.
When tracking snowshoes they will usually do a couple of things that are predictable.
They will circle back to where they were jumped... their home range isn't that big.
As you trail them they will often find a hump of snow, stump or log to sit on and watch their back trail... they'll often use the same place over and over.
If you just can't close the distance while tracking. Put a friend along the course the bunny likes to travel and push him toward your friend.
Or after a couple of times around, reverse direction and come at him from where he is going.
A good pair of binoculars helps a lot.