Allen gave me a great tip for sanding the LE. Is is all done.

Now what about the trailing edge of the wing. Any tips or tricks for sanding it?

I cut them on my table saw. I set it up to slice through a sheet of the proper thickness of balsa at the correct angle using a high tooth count (plywood) blade. Use some scrap to get the setup just right. After the first cut yields one trailing edge turning the sheet flat with the blade vertical allows me to cut a second TE from the the same sheet. Slice off the rear edge to get the thickness on the rear margin you need and a bit of sanding gives a perfect TE.
There are lots of ways to skin a cat and I'm sure others will chime in with their methods.

Yea the wing is built.

Guess I need need to blend it in to the TE sheeting?

here's a couple of pics to show how I did it using 1/64 ply, and what Ty and Neville suggest.

I use the razor saw recommended by Bob Hunt many years ago.  Comes from Hobby Lobby and is German made.  I will have to look up the brand name, but it is light metallic blue and uses double edge razor blades.  Much easier (blades are sharper) and more accurate than the Master Airscrew composite one.  Still I used that until I got the "good" one.  It will shave balsa down to where you can easily see through the strips so you don't take too much off in one pass.  Try to make a "complete", even, pass from end to end.  Try to hold the plane at the same angle as the TE sheeting at the rear edge to start.  You can see as the strip being removed is the same width all the way across the span and will get wider as you get down to the right shape.  Finish off with a long sanding block as others say.

Big Bear