Well ...............
First you need a
Felling Axe to cut the tree down and chop it to length.
Then you need a
Chopping Axe to split out some blanks. Or you can use a
Froe and
Mallet to split down longer length handle blanks.
Next, you'll need to built a
Draw Bench. You can do this during the 1 to 2 year wait while your wood seasons properly.
After that, you can sit at the Draw Bench and use your
Draw Knife to carve out your handle.
WHAT ! You don't have a Draw Knife ? What kind of handle maker are you ?

Well, I guess that's another tool you'll need to purchase.
Once you're done roughing out the handle blank, you can use your
Rasp to refine the shape and fit the top to the hole in the head of your tool.
Now that your handle is roughed out, you can smooth it down with
Crocus Cloth, originally made with fine crushed Blacksmith's Crocus imbedded in a cloth with a slight linseed oil binder (don't know what Crocus is ? It's the fine flakes that come off the cooling metal as the blacksmith is working hot iron on the anvil) .
Finally, use your
Backsaw to cut a slot in the head of the handle for the wedge that will lock the handle into the head.
(
don't forget to make a wedge)
Handles are simple to make.
EDIT - RivennHewn, nicely done.